Deploy RDO using Fuel

Last couple releases Fuel focused on DEB based distributions, but before we used to deploy OpenStack on CentOS and there is nothing preventing us from making it possible to deploy RDO using Fuel.

There are two major work items here:
1) Add fuel packages to RDO distribution (here is the doc [1])
2) Implement RPM image building in Bareon (fork of Fuel-agent). Currently we build OS images on the Fuel master node using Fuel-agent, but we used to build images together with Fuel ISO and there is old code that could be useful [2]

[1] https://www.rdoproject.org/documentation/rdo-packaging/
[2] https://github.com/openstack/fuel-main/tree/stable/6.1/image/centos