gate-tempest-dsvm-large-ops fails in stable/juno due to uncapped dep problems with osc

Tracking in https://etherpad.openstack.org/p/stable-tracker with steps on how I think we can unwedge juno.

ML thread: http://lists.openstack.org/pipermail/openstack-dev/2015-August/071628.html

I think installing the needed deps at the start of the job would avoid the problem, since we deliberately don't use -U within devstack.

Fix proposed to branch: stable/juno
Review: https://review.openstack.org/212135

Reviewed: https://review.openstack.org/212135
Committed: https://git.openstack.org/cgit/openstack-dev/devstack/commit/?id=001b1cdddc8cda6dd9eea51ef91eec589dfd88e6
Submitter: Jenkins
Branch: stable/juno

commit 001b1cdddc8cda6dd9eea51ef91eec589dfd88e6
Author: Matt Riedemann <email address hidden>
Date: Wed Aug 12 11:14:23 2015 -0700

    Workaround large-ops wedge with uncapped novaclient in osc 1.0.1

    python-openstackclient 1.0.1 pulls in uncapped novaclient which breaks
    the caps for novaclient in other projects in Juno. This only happens in
    the large-ops job because cinder isn't installed and therefore cinder
    doesn't install capped novaclient per juno global-requirements before osc
    is installed. We can't fix osc and bump it to 1.0.2 since osc is capped
    at <=1.0.1 in global-requirements for stable/juno, so we're stuck.

    So the workaround is to install python-novaclient from
    global-requirements prior to installing python-openstackclient but only
    in the case of the large-ops job, which we identify from the usage of
    the fake virt driver.

    Closes-Bug: #1482350

    Change-Id: Id8cc112800d757bfd509cc48087b769410356920