Update the logic to use stable branch of puppet-ceph
Update the logic to use stable branch of puppet-ceph

... so that we don't need to update it when switching Ceph to a new
release.

Change-Id: Ic3f0ccfa5a423b3ec48fc7bd9f289e31813d1176

openstack/puppet-openstack-integration,openstack/puppet-openstack-integration,openstack/puppet-openstack-integration