Update ModelManager.php
Merge pull request #253 from lucasgranberg/patch-2

Update ModelManager.php
Fixed typos
allow 2.2.11
Merge pull request #258 from pborreli/typos

Fixed typos
Merge pull request #257 from sonata-project/admin-bundle-2-2-11

allow 2.2.11
drop Symfony 2.2 support