Issue #3033367 by neclimdul, Joseph Zhao: Fix vfsstream composer deprecation warning

core/composer.json

@@ -58,7 +58,7 @@
         "drupal/coder": "^8.2.12",
         "jcalderonzumba/gastonjs": "^1.0.2",
         "jcalderonzumba/mink-phantomjs-driver": "^0.3.1",
-        "mikey179/vfsStream": "^1.2",
+        "mikey179/vfsstream": "^1.2",
         "phpunit/phpunit": "^4.8.35 || ^6.5",
         "phpspec/prophecy": "^1.7",
         "symfony/css-selector": "^3.4.0",