Require SA-Migrate 0.7.2 and SA 0.7.3 or greater

[Rick Harris]

Migrate 075 appears to do some fanciness which breaks under sa-migrate 0.7.1: http://paste.openstack.org/show/4735/

Upgrading sqlalchemy and sa-migrate fixes this; so we should require >= the latest.

$ pip freeze | grep lchem

SQLAlchemy==0.7.3
sqlalchemy-migrate==0.7.2

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/3883

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/3883
Committed: http://github.com/openstack/nova/commit/71247a627e367e8732f583fb4e197c23f0b5ec6f
Submitter: Jenkins
Branch: master

commit 71247a627e367e8732f583fb4e197c23f0b5ec6f
Author: Rick Harris <email address hidden>
Date: Wed Feb 8 05:33:40 2012 +0000

    Require newer versions of SA and SA-Migrate

    Fixes bug 928637

    Change-Id: I27d06d945449f70a6da00c1f5d306bd5fe43b253