When creating the schema for test these tables use default length for
string: 255. Which fail when using utf8mb4.
> Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes
Also move the `setKeepStaticConnections` in before and after class to
avoid:
> SAVEPOINT DOCTRINE2_SAVEPOINT_2 does not exist
See https://github.com/dmaicher/doctrine-test-bundle#troubleshooting
