Extract Assignment related tests from IdentityTestCase

+1 this probably should have been done during havana development, when the "assignment" backend was split out of "identity." So, there's some logic (historically) to how the tests are structured, but they should be refactored to reflect the modern division between identity and assignment.

Samuel, I have a couple test cases that are up for review that will have to be a part of this refactor. Since we are close to RC1, I held back on the refactor until development opens for Kilo. So far, I've been tagging tests in test_v3_identity.py with:

# TODO(lbragstad): Move this test to tests/test_v3_assignment.py

https://review.openstack.org/#/c/119843/5/keystone/tests/test_v3_identity.py

Lance, thank you for this info. I'm gonna take yours tests and put them on test_v3_assignment if your patch get merged first.

Fix proposed to branch: master
Review: https://review.openstack.org/121653

Reviewed: https://review.openstack.org/121653
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=87d14849512bc890514827923db3ed323b1b4071
Submitter: Jenkins
Branch: master

commit 87d14849512bc890514827923db3ed323b1b4071
Author: Samuel de Medeiros Queiroz <email address hidden>
Date: Mon Sep 15 15:38:18 2014 -0300

    Extract Assignment tests from IdentityTestCase

    Extracts tests for domains, projects, roles and
    grants/role assignments from IdentityTestCase
    and put them in AssignmentTestCase.

    Change-Id: I0e426fa1803e144b1c7a3eb503b212c6469e67c4
    Closes-Bug: 1367778

Fix proposed to branch: feature/hierarchical-multitenancy
Review: https://review.openstack.org/138182

Change abandoned by Morgan Fainberg (<email address hidden>) on branch: feature/hierarchical-multitenancy
Review: https://review.openstack.org/138182