DB should be empy before runing tests

[Sergey Skripnick]

Initial data needed by some tests is creating in constructor of base class for tests (nova.test.TestCase). It should be done only in setUp method of tests where it is needed.

[Boris Pavlovic (boris-42)]

This blocks bp test-db-api that has high priority

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29639

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/29639
Committed: http://github.com/openstack/nova/commit/2b92ca1de7ad10d2777ac44b95da55467cca7a21
Submitter: Jenkins
Branch: master

commit 2b92ca1de7ad10d2777ac44b95da55467cca7a21
Author: Sergey Skripnick <email address hidden>
Date: Sat May 18 14:07:03 2013 +0300

    Moved sample network creation out of unittest base class constructor.

    This sample networks only needed in:

     nova.tests.api.ec2.test_cloud
     nova.tests.integrated.test_api_samples
     nova.tests.network.test_manager
     nova.tests.test_libvirt
     nova.tests.test_xenapi

    Moreover, base class constructor is not good place for sample
    data creation. Database should be empty before runing tests.

    Fixes: bug 1181502

    Change-Id: I8dcaa5b36a1da0c0928c9445c556d788d463844e