testcase didn't use the reference data correctly

[Dave Chen]

'test_create_project_invalid_domain_id' intends to test create project with invalid domain id, but it didn't use the invalid reference data but use a empty request body.
see: https://git.openstack.org/cgit/openstack/keystone/tree/keystone/tests/unit/test_v3_assignment.py#n612

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/198629
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=912a5c662a84c3971030af12bbf197705e7e6bd9
Submitter: Jenkins
Branch: master

commit 912a5c662a84c3971030af12bbf197705e7e6bd9
Author: Dave Chen <email address hidden>
Date: Mon Jul 6 15:47:37 2015 +0800

    Fix the invalid testcase

    The testcase intends to test the case of creating project with invalid
    domain id, but this invalid domain id is not used in the testcase.

    Change-Id: I14c358d6a769cfff26bc838c5b5162aaff5edc9e
    Closes-Bug: #1471671