Add Missing Unit Tests

[Flavio Percoco]

Two tests are missing from our unit test suite to handle recent regression:

* DELETE messages with expired claim ID

The blueprint mentioned testing update of an expired claim which is already tested in the `test_expired_claim` test.

(there was a bp for this https://blueprints.launchpad.net/zaqar/+spec/add-missing-unit-tests )

[Flavio Percoco (flaper87)]

@Sphoorti are you actively working on this?

[Sphoorti (sphoorti-joglekar)]

Currently I can't work on this. Hence unassigning myself.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/135189
Committed: https://git.openstack.org/cgit/openstack/zaqar/commit/?id=92c22f54f90320393b0d22648b317c614c9e4932
Submitter: Jenkins
Branch: master

commit 92c22f54f90320393b0d22648b317c614c9e4932
Author: Flavio Percoco <email address hidden>
Date: Tue Nov 18 09:05:32 2014 +0100

    Test message delete when claim expires

    The patch adds a test for message deletion after a claim has expired.
    The result of the test is that the message should be deleted.

    Unfortunately, some issues related to the state of the sqlalchemy driver
    make it quite hard for this test to work there without further changes.
    I'm proposing this patch with some skips in place for the scenarios
    where sqlalchemy is required, I'll propose a follow up patch to fix
    those issues and enable these tests.

    Closes-bug: #1369536

    Change-Id: Icb12eed18c37455ad3528fa6a84fb8f2d8fcf19f