/users calls is missing functional tests

Partly fixed by commit: https://review.openstack.org/#/c/446972/

Reviewed: https://review.openstack.org/446972
Committed: https://git.openstack.org/cgit/openstack/craton/commit/?id=5f0e8d762214618b05b54a3f1594c697bf304d86
Submitter: Jenkins
Branch: master

commit 5f0e8d762214618b05b54a3f1594c697bf304d86
Author: Sulochan Acharya <email address hidden>
Date: Fri Mar 17 11:24:19 2017 +0000

    Create user under project_id passed in request

    Currently when user is created, its taking the project_id
    parameter from the user who is creating the request.
    However, given root users are expected to be ablet to create
    users for all projects this patch modifies the behaviour
    and ensure that the user creation is always under the
    project_id parameter that is passed in.

    Functional test for create call is added. However,
    function test coverage is not complete. It needs to
    be addressed as a separate commit, tacked in
    issue: 1674287

    Closes Bug: 1666695
    Partial-Bug: 1674287
    Parent: Ie5fac9ef4c305ff7e67fe32855ca8100a8adfa82

    Change-Id: I19fb901ad41edeeb0a92f41264867a768a207fce