Updated openstack/openstack
Project: openstack/heat  14381760d3cad0dd1367415ce41a0a4ea521fc1d

ResourceGroup subclass build resource definition

This refactor allows a ResourceGroup subclass to contribute its own
resource definition by overriding method _build_resource_definition.

Change-Id: I4176935f0fe3af900501852ffda621e708c36d24
Partial-Blueprint: deployment-multiple-servers