Add Ansible support for Heat

This changes bootstrapping of the Heat container to bootstrap
the Heat container with a heat domain user.  This requires some
work from bootstrap.yml to pass in several environment variables
needed by the heat domain setup script.

Co-Authored-By: Sam Yaple <sam@yaple.net>
Change-Id: Iab05983754fa514835cb5ff54d775faa18773110
Partially-implements: blueprint ansible-heat