DRY up URL version prefix usage in WSGI tests

[Kurt Griffiths]

Rather than writing this sort of thing all over the place:

    self.simulate_put(self.url_prefix + '/queues/fizbat', '7e55e1a7e')

We should be able to set the prefix once, and write this instead:

    self.simulate_put('/queues/fizbat', '7e55e1a7e')

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/78400

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/78400
Committed: https://git.openstack.org/cgit/openstack/marconi/commit/?id=2d53d8840e99e337dcb90eeb1ddce7129e4524c4
Submitter: Jenkins
Branch: master

commit 2d53d8840e99e337dcb90eeb1ddce7129e4524c4
Author: Victoria Martínez de la Cruz <email address hidden>
Date: Wed Mar 5 16:35:18 2014 -0300

    Slighty refactored url_prefix usage in WSGI tests

    Several calls to url_prefix has been replaced
    with the usage of a common variable in WSGI tests
    in order to adjust to DRY principles.

    Change-Id: I056e1e8879a97f6a30aff924e55bdf50897c08e4
    Closes-Bug: #1285219