Moved keystone db sync to its own class

This will decouple allowing for additions, like the apache wsgi
patch, so it can be included or triggered elsewhere.

Original author is François Charlier<francois.charlier@enovance.com>

Change-Id: I9ae544d58034ca30ddb0a4c616ff794ccd432d7f
Merge git://github.com/puppetlabs/puppetlabs-keystone