feat: add CoreOS support for halcyon

[v1k0d3n]

many people would like to see this feature added, especially when we're talking for projects like openstack-helm and kolla-kubernetes.

i'd like to see CoreOS supported for the project, and this issue is just to track this and let the community know that this is the project's intention. i know we're going to run into issues with Ceph support, but it's possible that this could get easier with things like a Ceph Helm Chart.