Add Ceilometer to Quickstack

* All services install fine, but `mongodb` and `ceilometer` Puppet modules need to be manually added to Foreman host currently.

* To solve the manual ^^ installation `packstack-modules-puppet` package in http://repos.fedorapeople.org/repos/openstack/openstack-havana/epel-6/ needs `mongodb` and `ceilometer` modules, as added here: https://review.openstack.org/#/c/41245

* I couldn't get any metering data on the Ceilometer master, but neither any complaints in the compute agent log. I need to investigate what's wrong.