Updated openstack/openstack
Project: openstack/heat  d9719175605b5e9bcf03481f79291e58e9431e02

sqlalchemy migration not to import model

sqlalchemy migration scripts should depend on
reflections rather than import model.py
Model denotes the latest state and will fail
if used in migration scripts

Change-Id: I4fcc3d06b96fab07ed47d5cc1fc4040395a60be8
Closes-Bug: #1380479