feat: add Atomic support for halcyon #55
Description
similar to CoreOS and #54, a lot of people would like to see support for Atomic as well.
this issue is just to track this effort and let the community know that there is an intention to support more base OS's. Ceph support could potentially be easier in Atomic than CoreOS, but it's something we'd like to have in place in order to support both the openstack-helm and kolla-kubernetes.