[nailgun] ./manage.py dropdb doesn't work in case of changed schema

[Vitaly Kramskikh]

sqlalchemy.exc.InternalError: (InternalError) cannot drop table clusters because other objects depend on it
DETAIL: constraint nodegroups_cluster_id_fkey on table nodegroups depends on table clusters
HINT: Use DROP ... CASCADE to drop the dependent objects too.
 '\nDROP TABLE clusters' {}

Caused by https://review.openstack.org/#/c/93286/

I suggest to revert it or reimplement properly

[Aleksandra Fedorova (bookwar)]

Log for tests runnning on already merged code:

https://fuel-jenkins.mirantis.com/job/stackforge-verify-fuel-web/3802/consoleFull

Fuel CI tests are broken, which blocks the review process for fuel-web repo. Changing to critical.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/99311

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/99300
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=34c1ad5dc97f13833da3c8e19ceb71f4d1bb8578
Submitter: Jenkins
Branch: master

commit 34c1ad5dc97f13833da3c8e19ceb71f4d1bb8578
Author: Nikolay Markov <email address hidden>
Date: Wed Jun 11 13:15:05 2014 +0400

    Fix for dropdb()

    Change-Id: I2cd4862f02dedaa034aad75900b3a8a2d32da8b9
    Closes-Bug: #1323350