Updated openstack/openstack
Project: openstack/heat  197ef72a780028f429652a15e0f6a73548921dd6

unit tests: Check validation in VPC test

Checking for errors from creating a stack is not a representative test,
since in practice all stacks are validated before being created.

Change-Id: Ie6ef2c07648e4e9bd0375c56c99c8b03576fe7f8