Trove db sync does not work correctly with pgsql

[Nikhil Manchanda]

This causes a trove install on devstack using pgsql to fail.
This needs to be fixed so that trove can be part of the integrated gate.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/81073

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/81073
Committed: https://git.openstack.org/cgit/openstack/trove/commit/?id=f984db30c4d4cab1377d21a73ec0b802590f8a51
Submitter: Jenkins
Branch: master

commit f984db30c4d4cab1377d21a73ec0b802590f8a51
Author: Nikhil Manchanda <email address hidden>
Date: Mon Mar 17 13:29:39 2014 -0700

    Update sqlalchemy migrate scripts for postgres

    pgsql <= 8.3 was lax about char->other casting but this was tightened
    up in 8.4+. We must now specify the USING clause for such a cast to
    succeed. The SQL queries generated by sqlalchemy for pgsql don't
    support this, so an override is needed to support pgsql for the trove
    migrate scripts.

    Closes-bug: 1293465
    Change-Id: I217fc861036911e61bafe706e338bb3b8f49e708