Customized ezplatform branch used for behat execution

Author: Bertrand Dunogier

composer.json

@@ -41,7 +41,7 @@
             "dev-master": "1.0.x-dev",
             "dev-tmp_ci_branch": "1.0.x-dev"
         },
-        "_ezplatform_branch_for_behat_tests": "2.5"
+        "_ezplatform_branch_for_behat_tests": "behat_graphql"
     },
     "scripts": {
         "fix-cs": "@php ./vendor/bin/php-cs-fixer fix -v --show-progress=estimating"