Updated openstack/openstack
Project: openstack/neutron  f154510a7c935e2b06b4ab25340084e4304cfcf7

Freeze models for healing migration

Take a snapshot of all models from the code base at the time when the
healing migration merges. The healing migration needs this frozen view
of the models to be available (even as the models change in the future)
to compare with the current DB schema. The healing migration will use
this comparison to heal the schema.

partially implement bp: db-migration-refactor

Change-Id: I438147c7961b1ecad47f6146cc7fc9396aee7bc5