Bug 1052674: added support for Swift cache
Bug 1052674: added support for Swift cache

This patch merely address the Swift cache backward compatibility support.

There's another BP which address the elephant-in-the-room, which is
unified and consistent caching mechanism for all middleware.

See https://blueprints.launchpad.net/keystone/+spec/unifed-caching-system-for-middleware

Change-Id: Iab6b4ac61c9aa9e7ad32a394557cb7558bd60a43

varunarya10/keystonemiddleware