Add compressed_ha_cephall and cephosd roles

In order to achive HA for volume service, we need Ceph.
This commit adds two roles: one which is identical to
the existing compressed_ha role but with the ceph_all group
added (deployes mon and osd) and another with is also identical
but deploys an osd only.
Add ceph mon role to compressed_ha

This commit adds a role for compressed_ha nodes that want
a Ceph mon (but not an osd).
Merge pull request #21 from CiscoSystems/add_ceph

Add compressed_ha_cephall and cephosd roles