diff --git a/composer.json b/composer.json
index d560b841b7005325963a919271434f29be83de10..8612c77ac221ba3933816e0dd51a33e362a52b0d 100644
--- a/composer.json
+++ b/composer.json
@@ -5,23 +5,10 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "composer/installers": "^1.0.24",
-        "drupal/core": "self.version"
+        "wikimedia/composer-merge-plugin": "^1.4"
     },
-    "require-dev": {
-        "behat/mink": "1.7.x-dev",
-        "behat/mink-goutte-driver": "^1.2",
-        "behat/mink-selenium2-driver": "1.3.x-dev",
-        "composer/composer": "^1.8",
-        "drupal/coder": "^8.3.2",
-        "jcalderonzumba/gastonjs": "^1.0.2",
-        "jcalderonzumba/mink-phantomjs-driver": "^0.3.1",
-        "mikey179/vfsstream": "^1.2",
-        "phpunit/phpunit": "^6.5",
-        "phpspec/prophecy": "^1.7",
-        "symfony/css-selector": "^3.4.0",
-        "symfony/phpunit-bridge": "^3.4.3",
-        "symfony/debug": "^3.4.0",
-        "justinrainbow/json-schema": "^5.2"
+    "replace": {
+        "drupal/core": "^8.8"
     },
     "minimum-stability": "dev",
     "prefer-stable": true,
@@ -37,8 +24,16 @@
             "You can read more about this composer repository at:",
             "https://www.drupal.org/node/2718229"
         ],
+        "merge-plugin": {
+            "include": [
+                "core/composer.json"
+            ],
+            "recurse": true,
+            "replace": false,
+            "merge-extra": false
+        },
         "installer-paths": {
-            "vendor/drupal/core": ["type:drupal-core"],
+            "core": ["type:drupal-core"],
             "modules/contrib/{$name}": ["type:drupal-module"],
             "profiles/contrib/{$name}": ["type:drupal-profile"],
             "themes/contrib/{$name}": ["type:drupal-theme"],
@@ -64,14 +59,6 @@
         {
             "type": "composer",
             "url": "https://packages.drupal.org/8"
-        },
-        {
-            "type": "path",
-            "url": "core"
-        },
-        {
-            "type": "path",
-            "url": "core/lib/Drupal/Component/Scaffold"
         }
     ]
 }
diff --git a/composer.lock b/composer.lock
index 9909f0eb7eb12bdcb09360a9259f85956ead8aa7..c43e82677e31e301647b1b29ddcf8006319d1c85 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "9008ba584ffe887b669b7e866b9c3b52",
+    "content-hash": "15aa825e18c7099ad637f9d55109db29",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -674,244 +674,6 @@
             ],
             "time": "2014-09-09T13:34:57+00:00"
         },
-        {
-            "name": "drupal/core",
-            "version": "8.8.x-dev",
-            "dist": {
-                "type": "path",
-                "url": "core",
-                "reference": "01c00e5f31b4629a7672bf1ef35de521a5bac7f0"
-            },
-            "require": {
-                "asm89/stack-cors": "^1.1",
-                "composer/semver": "^1.0",
-                "doctrine/annotations": "^1.2",
-                "doctrine/common": "^2.5",
-                "drupal/core-composer-scaffold": "self.version",
-                "easyrdf/easyrdf": "^0.9",
-                "egulias/email-validator": "^2.0",
-                "ext-date": "*",
-                "ext-dom": "*",
-                "ext-filter": "*",
-                "ext-gd": "*",
-                "ext-hash": "*",
-                "ext-json": "*",
-                "ext-pcre": "*",
-                "ext-pdo": "*",
-                "ext-session": "*",
-                "ext-simplexml": "*",
-                "ext-spl": "*",
-                "ext-tokenizer": "*",
-                "ext-xml": "*",
-                "guzzlehttp/guzzle": "^6.2.1",
-                "masterminds/html5": "^2.1",
-                "pear/archive_tar": "^1.4",
-                "php": ">=7.0.8",
-                "stack/builder": "^1.0",
-                "symfony-cmf/routing": "^1.4",
-                "symfony/class-loader": "~3.4.0",
-                "symfony/console": "~3.4.0",
-                "symfony/dependency-injection": "~3.4.26",
-                "symfony/event-dispatcher": "~3.4.0",
-                "symfony/http-foundation": "~3.4.27",
-                "symfony/http-kernel": "~3.4.14",
-                "symfony/polyfill-iconv": "^1.0",
-                "symfony/process": "~3.4.0",
-                "symfony/psr-http-message-bridge": "^1.0",
-                "symfony/routing": "~3.4.0",
-                "symfony/serializer": "~3.4.0",
-                "symfony/translation": "~3.4.0",
-                "symfony/validator": "~3.4.0",
-                "symfony/yaml": "~3.4.5",
-                "twig/twig": "^1.38.2",
-                "typo3/phar-stream-wrapper": "^2.1.1",
-                "zendframework/zend-diactoros": "^1.1",
-                "zendframework/zend-feed": "^2.4"
-            },
-            "conflict": {
-                "drush/drush": "<8.1.10"
-            },
-            "replace": {
-                "drupal/action": "self.version",
-                "drupal/aggregator": "self.version",
-                "drupal/automated_cron": "self.version",
-                "drupal/ban": "self.version",
-                "drupal/bartik": "self.version",
-                "drupal/basic_auth": "self.version",
-                "drupal/big_pipe": "self.version",
-                "drupal/block": "self.version",
-                "drupal/block_content": "self.version",
-                "drupal/block_place": "self.version",
-                "drupal/book": "self.version",
-                "drupal/breakpoint": "self.version",
-                "drupal/ckeditor": "self.version",
-                "drupal/classy": "self.version",
-                "drupal/color": "self.version",
-                "drupal/comment": "self.version",
-                "drupal/config": "self.version",
-                "drupal/config_environment": "self.version",
-                "drupal/config_translation": "self.version",
-                "drupal/contact": "self.version",
-                "drupal/content_moderation": "self.version",
-                "drupal/content_translation": "self.version",
-                "drupal/contextual": "self.version",
-                "drupal/core-annotation": "self.version",
-                "drupal/core-assertion": "self.version",
-                "drupal/core-bridge": "self.version",
-                "drupal/core-class-finder": "self.version",
-                "drupal/core-datetime": "self.version",
-                "drupal/core-dependency-injection": "self.version",
-                "drupal/core-diff": "self.version",
-                "drupal/core-discovery": "self.version",
-                "drupal/core-event-dispatcher": "self.version",
-                "drupal/core-file-cache": "self.version",
-                "drupal/core-filesystem": "self.version",
-                "drupal/core-gettext": "self.version",
-                "drupal/core-graph": "self.version",
-                "drupal/core-http-foundation": "self.version",
-                "drupal/core-php-storage": "self.version",
-                "drupal/core-plugin": "self.version",
-                "drupal/core-proxy-builder": "self.version",
-                "drupal/core-render": "self.version",
-                "drupal/core-serialization": "self.version",
-                "drupal/core-transliteration": "self.version",
-                "drupal/core-utility": "self.version",
-                "drupal/core-uuid": "self.version",
-                "drupal/core-version": "self.version",
-                "drupal/datetime": "self.version",
-                "drupal/datetime_range": "self.version",
-                "drupal/dblog": "self.version",
-                "drupal/dynamic_page_cache": "self.version",
-                "drupal/editor": "self.version",
-                "drupal/entity_reference": "self.version",
-                "drupal/field": "self.version",
-                "drupal/field_layout": "self.version",
-                "drupal/field_ui": "self.version",
-                "drupal/file": "self.version",
-                "drupal/filter": "self.version",
-                "drupal/forum": "self.version",
-                "drupal/hal": "self.version",
-                "drupal/help": "self.version",
-                "drupal/help_topics": "self.version",
-                "drupal/history": "self.version",
-                "drupal/image": "self.version",
-                "drupal/inline_form_errors": "self.version",
-                "drupal/jsonapi": "self.version",
-                "drupal/language": "self.version",
-                "drupal/layout_builder": "self.version",
-                "drupal/layout_discovery": "self.version",
-                "drupal/link": "self.version",
-                "drupal/locale": "self.version",
-                "drupal/media": "self.version",
-                "drupal/media_library": "self.version",
-                "drupal/menu_link_content": "self.version",
-                "drupal/menu_ui": "self.version",
-                "drupal/migrate": "self.version",
-                "drupal/migrate_drupal": "self.version",
-                "drupal/migrate_drupal_multilingual": "self.version",
-                "drupal/migrate_drupal_ui": "self.version",
-                "drupal/minimal": "self.version",
-                "drupal/node": "self.version",
-                "drupal/options": "self.version",
-                "drupal/page_cache": "self.version",
-                "drupal/path": "self.version",
-                "drupal/quickedit": "self.version",
-                "drupal/rdf": "self.version",
-                "drupal/responsive_image": "self.version",
-                "drupal/rest": "self.version",
-                "drupal/search": "self.version",
-                "drupal/serialization": "self.version",
-                "drupal/settings_tray": "self.version",
-                "drupal/seven": "self.version",
-                "drupal/shortcut": "self.version",
-                "drupal/simpletest": "self.version",
-                "drupal/standard": "self.version",
-                "drupal/stark": "self.version",
-                "drupal/statistics": "self.version",
-                "drupal/syslog": "self.version",
-                "drupal/system": "self.version",
-                "drupal/taxonomy": "self.version",
-                "drupal/telephone": "self.version",
-                "drupal/text": "self.version",
-                "drupal/toolbar": "self.version",
-                "drupal/tour": "self.version",
-                "drupal/tracker": "self.version",
-                "drupal/update": "self.version",
-                "drupal/user": "self.version",
-                "drupal/views": "self.version",
-                "drupal/views_ui": "self.version",
-                "drupal/workflows": "self.version",
-                "drupal/workspaces": "self.version"
-            },
-            "type": "drupal-core",
-            "autoload": {
-                "psr-4": {
-                    "Drupal\\Core\\": "lib/Drupal/Core",
-                    "Drupal\\Component\\": "lib/Drupal/Component",
-                    "Drupal\\Driver\\": "../drivers/lib/Drupal/Driver"
-                },
-                "classmap": [
-                    "lib/Drupal.php",
-                    "lib/Drupal/Component/Utility/Timer.php",
-                    "lib/Drupal/Component/Utility/Unicode.php",
-                    "lib/Drupal/Core/Database/Database.php",
-                    "lib/Drupal/Core/DrupalKernel.php",
-                    "lib/Drupal/Core/DrupalKernelInterface.php",
-                    "lib/Drupal/Core/Site/Settings.php"
-                ]
-            },
-            "scripts": {
-                "pre-autoload-dump": [
-                    "Drupal\\Core\\Composer\\Composer::preAutoloadDump"
-                ],
-                "post-autoload-dump": [
-                    "Drupal\\Core\\Composer\\Composer::ensureHtaccess"
-                ]
-            },
-            "license": [
-                "GPL-2.0-or-later"
-            ],
-            "description": "Drupal is an open source content management platform powering millions of websites and applications."
-        },
-        {
-            "name": "drupal/core-composer-scaffold",
-            "version": "8.8.x-dev",
-            "dist": {
-                "type": "path",
-                "url": "core/lib/Drupal/Component/Scaffold",
-                "reference": "d3a39036c1a4d39ec64ebc22bda15031b950219d"
-            },
-            "require": {
-                "composer-plugin-api": "^1.0.0",
-                "php": ">=7.0.8"
-            },
-            "require-dev": {
-                "composer/composer": "^1.8@stable"
-            },
-            "type": "composer-plugin",
-            "extra": {
-                "class": "Drupal\\Component\\Scaffold\\Plugin",
-                "branch-alias": {
-                    "dev-master": "1.0.x-dev"
-                }
-            },
-            "autoload": {
-                "psr-4": {
-                    "Drupal\\Component\\Scaffold\\": ""
-                }
-            },
-            "license": [
-                "GPL-2.0-or-later"
-            ],
-            "description": "A flexible Composer project scaffold builder.",
-            "homepage": "https://www.drupal.org/project/drupal",
-            "keywords": [
-                "drupal"
-            ],
-            "transport-options": {
-                "symlink": true
-            }
-        },
         {
             "name": "easyrdf/easyrdf",
             "version": "0.9.1",
@@ -3081,6 +2843,55 @@
             ],
             "time": "2019-05-14T13:14:31+00:00"
         },
+        {
+            "name": "wikimedia/composer-merge-plugin",
+            "version": "v1.4.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/wikimedia/composer-merge-plugin.git",
+                "reference": "81c6ac72a24a67383419c7eb9aa2b3437f2ab100"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/wikimedia/composer-merge-plugin/zipball/81c6ac72a24a67383419c7eb9aa2b3437f2ab100",
+                "reference": "81c6ac72a24a67383419c7eb9aa2b3437f2ab100",
+                "shasum": ""
+            },
+            "require": {
+                "composer-plugin-api": "^1.0",
+                "php": ">=5.3.2"
+            },
+            "require-dev": {
+                "composer/composer": "~1.0.0",
+                "jakub-onderka/php-parallel-lint": "~0.8",
+                "phpunit/phpunit": "~4.8|~5.0",
+                "squizlabs/php_codesniffer": "~2.1.0"
+            },
+            "type": "composer-plugin",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.3.x-dev"
+                },
+                "class": "Wikimedia\\Composer\\MergePlugin"
+            },
+            "autoload": {
+                "psr-4": {
+                    "Wikimedia\\Composer\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Bryan Davis",
+                    "email": "bd808@wikimedia.org"
+                }
+            ],
+            "description": "Composer plugin to merge multiple composer.json files",
+            "time": "2017-04-25T02:31:25+00:00"
+        },
         {
             "name": "zendframework/zend-diactoros",
             "version": "1.4.1",
@@ -3291,7 +3102,7 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/minkphp/Mink.git",
-                "reference": "a534fe7dac9525e8e10ca68e737c3d7e5058ec83"
+                "reference": "9ea1cebe3dc529ba3861d87c818f045362c40484"
             },
             "dist": {
                 "type": "zip",
@@ -3341,7 +3152,7 @@
                 "testing",
                 "web"
             ],
-            "time": "2019-07-15T12:45:29+00:00"
+            "time": "2017-02-06T09:59:54+00:00"
         },
         {
             "name": "behat/mink-browserkit-driver",
@@ -4184,7 +3995,7 @@
             "time": "2019-01-14T23:55:14+00:00"
         },
         {
-            "name": "mikey179/vfsstream",
+            "name": "mikey179/vfsStream",
             "version": "v1.6.5",
             "source": {
                 "type": "git",
@@ -5959,12 +5770,26 @@
     "aliases": [],
     "minimum-stability": "dev",
     "stability-flags": {
-        "drupal/core": 20,
         "behat/mink": 20,
         "behat/mink-selenium2-driver": 20
     },
     "prefer-stable": true,
     "prefer-lowest": false,
-    "platform": [],
+    "platform": {
+        "ext-date": "*",
+        "ext-dom": "*",
+        "ext-filter": "*",
+        "ext-gd": "*",
+        "ext-hash": "*",
+        "ext-json": "*",
+        "ext-pcre": "*",
+        "ext-pdo": "*",
+        "ext-session": "*",
+        "ext-simplexml": "*",
+        "ext-spl": "*",
+        "ext-tokenizer": "*",
+        "ext-xml": "*",
+        "php": ">=7.0.8"
+    },
     "platform-dev": []
 }
diff --git a/core/composer.json b/core/composer.json
index 5214775b790ea986ef44251d79ac26611743e663..4fee977c236ebe1d9cf2a846c447d61278219777 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -18,7 +18,6 @@
         "ext-tokenizer": "*",
         "ext-xml": "*",
         "php": ">=7.0.8",
-        "drupal/core-composer-scaffold": "self.version",
         "symfony/class-loader": "~3.4.0",
         "symfony/console": "~3.4.0",
         "symfony/dependency-injection": "~3.4.26",
@@ -52,6 +51,22 @@
     "conflict": {
         "drush/drush": "<8.1.10"
     },
+    "require-dev": {
+        "behat/mink": "1.7.x-dev",
+        "behat/mink-goutte-driver": "^1.2",
+        "behat/mink-selenium2-driver": "1.3.x-dev",
+        "composer/composer": "^1.8",
+        "drupal/coder": "^8.3.2",
+        "jcalderonzumba/gastonjs": "^1.0.2",
+        "jcalderonzumba/mink-phantomjs-driver": "^0.3.1",
+        "mikey179/vfsstream": "^1.2",
+        "phpunit/phpunit": "^6.5",
+        "phpspec/prophecy": "^1.7",
+        "symfony/css-selector": "^3.4.0",
+        "symfony/phpunit-bridge": "^3.4.3",
+        "symfony/debug": "^3.4.0",
+        "justinrainbow/json-schema": "^5.2"
+    },
     "replace": {
         "drupal/action": "self.version",
         "drupal/aggregator": "self.version",
@@ -95,6 +110,7 @@
         "drupal/core-proxy-builder": "self.version",
         "drupal/core-render": "self.version",
         "drupal/core-serialization": "self.version",
+        "drupal/core-composer-scaffold": "self.version",
         "drupal/core-transliteration": "self.version",
         "drupal/core-utility": "self.version",
         "drupal/core-uuid": "self.version",
@@ -164,6 +180,39 @@
         "drupal/workflows": "self.version",
         "drupal/workspaces": "self.version"
     },
+    "extra": {
+        "merge-plugin": {
+            "require": [
+                "core/lib/Drupal/Component/Annotation/composer.json",
+                "core/lib/Drupal/Component/Assertion/composer.json",
+                "core/lib/Drupal/Component/Bridge/composer.json",
+                "core/lib/Drupal/Component/ClassFinder/composer.json",
+                "core/lib/Drupal/Component/Datetime/composer.json",
+                "core/lib/Drupal/Component/DependencyInjection/composer.json",
+                "core/lib/Drupal/Component/Diff/composer.json",
+                "core/lib/Drupal/Component/Discovery/composer.json",
+                "core/lib/Drupal/Component/EventDispatcher/composer.json",
+                "core/lib/Drupal/Component/FileCache/composer.json",
+                "core/lib/Drupal/Component/FileSystem/composer.json",
+                "core/lib/Drupal/Component/Gettext/composer.json",
+                "core/lib/Drupal/Component/Graph/composer.json",
+                "core/lib/Drupal/Component/HttpFoundation/composer.json",
+                "core/lib/Drupal/Component/PhpStorage/composer.json",
+                "core/lib/Drupal/Component/Plugin/composer.json",
+                "core/lib/Drupal/Component/ProxyBuilder/composer.json",
+                "core/lib/Drupal/Component/Render/composer.json",
+                "core/lib/Drupal/Component/Serialization/composer.json",
+                "core/lib/Drupal/Component/Scaffold/composer.json",
+                "core/lib/Drupal/Component/Transliteration/composer.json",
+                "core/lib/Drupal/Component/Utility/composer.json",
+                "core/lib/Drupal/Component/Uuid/composer.json",
+                "core/lib/Drupal/Component/Version/composer.json"
+            ],
+            "recurse": false,
+            "replace": false,
+            "merge-extra": false
+        }
+    },
     "minimum-stability": "dev",
     "prefer-stable": true,
     "autoload": {
diff --git a/core/tests/Drupal/Nightwatch/nightwatch.conf.js b/core/tests/Drupal/Nightwatch/nightwatch.conf.js
index ee98b2815f3c78ade8104d4c64fb7a636e748e71..7f4cb83529b8ef86640294b0b9c246b9562d1a44 100644
--- a/core/tests/Drupal/Nightwatch/nightwatch.conf.js
+++ b/core/tests/Drupal/Nightwatch/nightwatch.conf.js
@@ -10,16 +10,13 @@ const collectedFolders = {
   Pages: [],
 };
 const searchDirectory = process.env.DRUPAL_NIGHTWATCH_SEARCH_DIRECTORY || '';
-const defaultIgnore = ['vendor/**'];
 
 glob
   .sync('**/tests/**/Nightwatch/**/*.js', {
     cwd: path.resolve(process.cwd(), `../${searchDirectory}`),
     ignore: process.env.DRUPAL_NIGHTWATCH_IGNORE_DIRECTORIES
-      ? process.env.DRUPAL_NIGHTWATCH_IGNORE_DIRECTORIES.split(',').concat(
-          defaultIgnore,
-        )
-      : defaultIgnore,
+      ? process.env.DRUPAL_NIGHTWATCH_IGNORE_DIRECTORIES.split(',')
+      : [],
   })
   .forEach(file => {
     let m = regex.exec(file);