If the deployemnt environment supports it, and the user would like to,
we can use Juju's Availability Zone information to setup the Ceph
cluster to use Availability Zones as the failure domain instead of
the host.

Change-Id: I4566696750b388918761ded0ed5beb0bf82ff501
Depends-On: Ie25ac1b001db558d6a40fe3eaca014e8f4174241