Deprecate Ceph deployment

There are now several good tools for deploying Ceph, including Ceph
Ansible and ceph-deploy. Maintaining our own Ceph deployment is a
significant maintenance burden, and we should focus on our core mission
to deploy OpenStack. Given that this is a significant part of kolla
ansible currently we will need a long deprecation period and a migration
path to another tool.

Change-Id: Ic603c85c04d8794580a19f9efaa7a8589565f4f6
Partially-Implements: blueprint remove-ceph