Enable replica sets for compressed HA

Include mongodb replication as part of the data
model to enable compressed HA scenario

Recovering this lost commit which was merged into havana before but was overridden by coi-dev branch

Old PR: https://github.com/CiscoSystems/puppet_openstack_builder/pull/58

Lost Commit: https://github.com/CiscoSystems/puppet_openstack_builder/commit/b4500903b267dc52e0af69807b7603af3cad46b3