Reduce default token duration to one hour

Keystone has reduced it's default token duration to 1 hour for
Icehouse.  The same should be done in the Keystone puppet module.

Change-Id: Ia790682a3f7693b863193cc1b60e17d971af7e75
Implements: blueprint reduce-default-token-duration
Closes-bug: 1299334
Merge "Reduce default token duration to one hour"