Intermittent Unit Test Failures in Quota Enforcer

[Dave McCowan]

Sometimes when unit tests and coverage tests are running in the gate the following error occurs.
This seems to indicate that the database has not been initialized.

2015-09-19 19:33:46.970 | ======================================================================
2015-09-19 19:33:46.970 | FAIL: barbican.tests.common.test_quota.WhenTestingQuotaEnforcingFunctions.test_should_pass_below_limit
2015-09-19 19:33:46.970 | tags: worker-5
2015-09-19 19:33:46.970 | ----------------------------------------------------------------------
2015-09-19 19:33:46.970 | Empty attachments:
2015-09-19 19:33:46.970 | pythonlogging:''
2015-09-19 19:33:46.971 | stderr
2015-09-19 19:33:46.971 | stdout
2015-09-19 19:33:46.971 |
2015-09-19 19:33:46.971 | Traceback (most recent call last):
2015-09-19 19:33:46.971 | File "barbican/tests/common/test_quota.py", line 249, in test_should_pass_below_limit
2015-09-19 19:33:46.971 | five_project_quotas)
2015-09-19 19:33:46.971 | File "barbican/common/quota.py", line 110, in set_project_quotas
2015-09-19 19:33:46.971 | project = res.get_or_create_project(external_project_id)
2015-09-19 19:33:46.971 | File "barbican/common/resources.py", line 43, in get_or_create_project
2015-09-19 19:33:46.971 | suppress_exception=True)
2015-09-19 19:33:46.971 | File "barbican/model/repositories.py", line 564, in find_by_external_project_id
2015-09-19 19:33:46.972 | session = self.get_session(session)
2015-09-19 19:33:46.972 | File "barbican/model/repositories.py", line 332, in get_session
2015-09-19 19:33:46.972 | return session or get_session()
2015-09-19 19:33:46.972 | File "barbican/model/repositories.py", line 153, in get_session
2015-09-19 19:33:46.972 | return _SESSION_FACTORY()
2015-09-19 19:33:46.972 | TypeError: 'NoneType' object is not callable

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/225502