Fixtures in unit testing for a standalone bundle

i wrote a standalone bundle for symfony and doctrine, and i want to unit test it with phpunit i need a database, entities and fixtures to test my bundle. I followed this nice gist to create an App included into my bundle : http://ift.tt/2aA0Z9D

Everything is going nice, except for the doctrine mapping. I got a "No Metadata Classes to process." message each time i try to update the database. Here is my doctrine config :

    orm:
        auto_generate_proxy_classes: "%kernel.debug%"
        naming_strategy: doctrine.orm.naming_strategy.underscore
        mappings:
            C2is\DoctrineCacheInvalidationBundle\Tests\Fixtures\Entity:    
                type:                 annotation
                dir:                  "%kernel.root_dir%/../Entity"
                is_bundle:            false
                prefix:               DoctrineCacheInvalidationBundle\Entity
                alias:                DoctrineCacheInvalidationBundle

And inside the directory Entity i have an extremely simple Test.php entity, which is in namespace C2is\DoctrineCacheInvalidationBundle\Tests\Fixtures\Entity;

i can't figure any way to make doctrine understand the metadatas.

thanks for helping.