bumping to slick 2.0 from M2 (removes SQLDriver because it no longer exists in Slick 20)
Merge pull request #110 from v6ak/master

 When using a JDBC driver not known by Play-Slick, user can now specify the Slick driver explicitly.
Port pull request #110 to slick 2.0
If not found, try to load the driver class from the application class loader.
Merge branch 'config' into slick20-26