Implements: blueprint heat-template

Previously, the kolla heat template was maintained outside of
the project in the larsks/heat-kubernetes repo. This patch adds
the templates to the project's devenv directory. Additionally,
the patch updates the templates and documentation to reflect
the design changes outlined in the following spec:

https://github.com/stackforge/kolla/blob/master/specs/containerize-openstack.rst

Change-Id: I11305f87cceb2495478d458a7e381d20838e664a