Ensure ceph-ansible is installed
Ensure ceph-ansible is installed

Before attempting to install Ceph check that ceph-ansible is
installed using the new inflight-validations feature. If it
is not installed then fail the deployment using the message
from the validations frame work.

Change-Id: I6e9042f8cc2e5258e0e62c1bacaebf9a51eb61a7
Implements: blueprint inflight-validations
Depends-On: Ic099c61c74abf6da24a2cce899c944e3bf8ce26b

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates