Issue #2052923 by Berdir: Update Guzzle to latest version.

composer.json

composer.lock

...l/aggregator/Plugin/aggregator/fetcher/DefaultFetcher.php

core/modules/locale/locale.batch.inc

...stics/lib/Drupal/statistics/Tests/StatisticsAdminTest.php

...ics/lib/Drupal/statistics/Tests/StatisticsLoggingTest.php

...ics/lib/Drupal/statistics/Tests/Views/IntegrationTest.php

core/vendor/autoload.php

core/vendor/composer/autoload_real.php

core/vendor/composer/installed.json

...dor/guzzle/common/Guzzle/Common/AbstractHasDispatcher.php

core/vendor/guzzle/common/Guzzle/Common/Collection.php

core/vendor/guzzle/common/Guzzle/Common/Event.php

...le/common/Guzzle/Common/Exception/ExceptionCollection.php

...or/guzzle/common/Guzzle/Common/HasDispatcherInterface.php

core/vendor/guzzle/common/Guzzle/Common/Version.php

core/vendor/guzzle/common/Guzzle/Common/composer.json

...r/guzzle/http/Guzzle/Http/AbstractEntityBodyDecorator.php

core/vendor/guzzle/http/Guzzle/Http/CachingEntityBody.php

core/vendor/guzzle/http/Guzzle/Http/Client.php