Support for Ceilometer installation.

- Added puppet-ceilometer and puppetlabs-mongodb modules
- Added Ceilometer plugin

Fixes: rhbz#967310

Change-Id: Ib1f42faf78a75af32232994f8e40acbdac318b4d
Make sure agent config gets done on api hosts

Change-Id: I0bfec0ba88c81f458052dfa2d5c70127c6ba6cea
Merge "Support for Ceilometer installation."