Key manager drivers support schema migration.

* Script to run migration swift-key-manager-sync.
* KeyDriver interface extended by sync method.
* Intergration with SQLAlchemy Migration for SQLDriver.

Change-Id: I2c482e994668fcb55c6a3b11158ae3c65d43d33e
Fixing pep8

Change-Id: I05d6f12fa8d88e2cd57f9dc0f0faa76bfd26874e
Fix migration script.

Change-Id: I39cf20d3817d73cfad45f8f2d091197cd003cb06