Cinder containers: volume and env customizations
Cinder containers: volume and env customizations

This patch will allow custom volume and env variables for the
cinder-volume container.

This is likely going to be needed by some Cinder backends who may not
have in-tree TripleO integration yet and need these types of
customizations.

Change-Id: I825c5373c7c4ab6896579eae705bc034f67fb68f

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