quantum-db-manage failed with db migration scripts have branches

[Yoshihiro Kaneko]

down_revision of 1b693c095aa3_quota_ext_db_grizzly and
2a6d0b51f4bb_cisco_plugin_cleanup conflicted.

$ quantum-db-manage \
  --config-file /etc/quantum/quantum.conf \
  --config-file /etc/quantum/plugins/openvswitch/ovs_quantum_plugin.ini \
  stamp head
INFO [alembic.migration] Context impl MySQLImpl.
INFO [alembic.migration] Will assume non-transactional DDL.
  Only a single head supported so far...

$ quantum-db-manage \
  --config-file /etc/quantum/quantum.conf \
  --config-file /etc/quantum/plugins/openvswitch/ovs_quantum_plugin.ini \
  history

1d76643bcec4 -> 1b693c095aa3 (head), Quota ext support added in Grizzly

1d76643bcec4 -> 2a6d0b51f4bb (head), cisco plugin cleanup
3cb5d900c5de -> 1d76643bcec4 (branchpoint), nvp_netbinding
48b6f43f7471 -> 3cb5d900c5de, security_groups
5a875d0e5c -> 48b6f43f7471, DB support for service types
folsom -> 5a875d0e5c, ryu
None -> folsom, folsom initial database

[Akihiro Motoki (amotoki)]

When many parallel reviews are going, such cases can easily occur from now on.

My idea is that adding a proper db migration script check to PEP8 test.
Since PEP8 test is executed by Jenkins, we can avoid db migration script branches.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/20685

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/20685
Committed: http://github.com/openstack/quantum/commit/4510c3fb0742a4a00d1e15b0429a36d6fa476a85
Submitter: Jenkins
Branch: master

commit 4510c3fb0742a4a00d1e15b0429a36d6fa476a85
Author: Akihiro MOTOKI <email address hidden>
Date: Tue Jan 29 22:50:15 2013 +0900

    Fix branch in db migration scripts

    Fixes bug #1108781

    Change-Id: Ia6cfcc4a1cc39136bad99be26f40aac9fa3e3e70