Use doctrine cache for tests

app/config/config_test.yml

@@ -20,3 +20,10 @@ doctrine:
         driver: pdo_sqlite
         path: %kernel.root_dir%/../data/db/wallabag_test.sqlite
         host: localhost
+    orm:
+        metadata_cache_driver:
+            type: service
+            id: filesystem_cache
+        query_cache_driver:
+            type: service
+            id: filesystem_cache

app/config/services.yml

@@ -6,6 +6,8 @@ parameters:
     security.validator.user_password.class: Wallabag\CoreBundle\Security\Validator\WallabagUserPasswordValidator
 
 services:
-#    service_name:
-#        class: AppBundle\Directory\ClassName
-#        arguments: ["@another_service_name", "plain_value", "%parameter_name%"]
+    # used for tests
+    filesystem_cache:
+        class: Doctrine\Common\Cache\FilesystemCache
+        arguments:
+            - %kernel.cache_dir%/doctrine/metadata