Updated openstack/openstack
Project: openstack/heat  3a642f5da233aab883d1061f55be89fee86f94b8

Update docs to reflect HOT version support.

This patch updates hot_spec.rst and functions.rst to reflect the changes
made to HOT version support.

Change-Id: I61f77ba30b59d5954201072f59b03cbd3d67debd
Closes-bug: #1386184