Fix the cache interface to use time= by default.
Fix the cache interface to use time= by default.

Historically the swift cache conection used the argument timeout= for
the cache timeout, but this has been unified with the official python
memcache client with time= since grizzly, we still need to handle folsom
for a while until this could get removed.

Fixes bug 1193032

Change-Id: Ia9d544a0277beb197ed9824d7c1266d12968393d

varunarya10/keystonemiddleware