[firstapp] use openstack command instead of heat command
[firstapp] use openstack command instead of heat command

The heat command is deprecated in favor of the openstack command.

Change-Id: Ia291cde09cbb0b695e54a82211ea3d3df339370b
Closes-Bug: #1581726

openstack/api-site,openstack/api-site,openstack/api-site,openstack/api-site