Remove dependency on KnpMenuBundle.

Removes sonata.block.service.menu when KnpMenuBundle isn't active.
Merge pull request #120 from kibao/fix-knp-menu-bundle-dependency

Remove dependency on KnpMenuBundle.
Fixed configuration test
Merge pull request #121 from Bladrak/fixedConfigTest

Fixed configuration test
Merge branch 'sonata-project/master'