Use weak deprecation testing

Author: curry684

.travis.yml

@@ -20,15 +20,15 @@ matrix:
      - php: 7.2
        env:
          - COMPOSER_FLAGS="--prefer-lowest"
-         - SYMFONY_DEPRECATIONS_HELPER=weak_vendors
+         - SYMFONY_DEPRECATIONS_HELPER=weak
      - php: 7.3
        env:
          - SYMFONY_VERSION=^4.4
-         - SYMFONY_DEPRECATIONS_HELPER=weak_vendors
+         - SYMFONY_DEPRECATIONS_HELPER=weak
      - php: 7.4
        env:
          - SYMFONY_VERSION=^4.4
-         - SYMFONY_DEPRECATIONS_HELPER=weak_vendors
+         - SYMFONY_DEPRECATIONS_HELPER=weak
      - php: 7.4
        env:
          - DEPENDENCIES=dev