Expose role tags via heat RoleTags output
Expose role tags via heat RoleTags output

This will enable easier consumption of the tags e.g via
the dynamic ansible inventory or workflows that run ansible

Change-Id: I8810240d012ff369991e5e6098e36aa3713e2615

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