Add release config for tripleo-heat-templates

We want to start releasing tripleo-heat-templates, so this
will add the configuration required to make it happen.

Co-Authored-By: Roman Podoliaka <rpodolyaka@mirantis.com>

Change-Id: I246c972fc9f6d6fbcb138106a3ee58fe84146dfd
Merge "Add release config for tripleo-heat-templates"