Hard delete for auth stuff

Access tokens and Authorization codes will now be deleted from the DB.
Refresh tokens were moved to a separate table, as the should live
forever.

Change-Id: Iff38b5e1313d139f37ba03e957f038c84baf61dd
Logging configuration improvement

Restrict logging to WARN from oslo db module.
Otherwise it spams unnecessary messages like these
http://postimg.org/image/4fpn53ncv/27e653ee/

Change-Id: Ic16b5ba34ad8b3e0254dc2177e9ed10e4d4272b6
Merge "Hard delete for auth stuff"
Merge "Logging configuration improvement"