do not report deprecations in vendors

Author: dbu

.travis.yml

@@ -28,7 +28,7 @@ cache:
 env:
   matrix: SYMFONY_VERSION=4.0.*
   global:
-    - SYMFONY_DEPRECATIONS_HELPER=0
+    - SYMFONY_DEPRECATIONS_HELPER=weak_vendors
     - SYMFONY_PHPUNIT_DIR=.phpunit SYMFONY_PHPUNIT_REMOVE="symfony/yaml"
     - KERNEL_CLASS=Symfony\Cmf\Bundle\SonataPhpcrAdminIntegrationBundle\Tests\Fixtures\App\Kernel
     - SYMFONY_PHPUNIT_VERSION=5.7