Updated openstack/openstack
Project: openstack/heat  b537bdf9bd255e329c55ef1ce4c938e6abc0e21c

remove bogus comments re stack_delete_after in tests

We no longer use the stack_delete_after decorator, so move these old
comments referring to it

Change-Id: Ib7e9f190cdee3bc337542c1d61736c5fa530216c