large-ops scenario deletes VMs after each test case instead of leaving them to be cleaned at the end of the test class

[Yair Fried]

Large Ops scenario is design to test the bulk creation of VMs while multiple VMs already exist in tenant.
Due to some refactoring in Tempest scenario, the VMs are now deleted at the end of the individual test cases.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/136981

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/136981
Committed: https://git.openstack.org/cgit/openstack/tempest/commit/?id=6cad13618708608962afd92dc7fa077bf352a580
Submitter: Jenkins
Branch: master

commit 6cad13618708608962afd92dc7fa077bf352a580
Author: Yair Fried <email address hidden>
Date: Mon Nov 24 17:56:56 2014 +0200

    Cleanup class resources for large-ops scenario

    Large Ops scenario is design to test the bulk creation of VMs while multiple
    VMs already exist in tenant.
    Due to some refactoring in Tempest scenario, the VMs are now deleted at the end
    of the individual test cases.

    Removes usage of addCleanup() from large-ops scenario.

    Adds Class level method - addCleanupClass to cleanup resources at the end of
    the test class.

    Closes-Bug: #1395759
    Change-Id: I612fcfab83a2046b8e597e009e385d7918f943b9