BZ #1127236 - Create cron job to flush the keystone tokens.

https://bugzilla.redhat.com/show_bug.cgi?id=1127236

Since puppet-keystone does not set this up, add to quickstack.
Merge pull request #378 from jguiditta/BZ1127236-keystone-cron

BZ #1127236 - Create cron job to flush the keystone tokens.