Comment 10 for bug 1821824

Reviewed: https://review.openstack.org/649601
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=6a5be4ae250b9ff1b8e48947ab80a65827460513
Submitter: Zuul
Branch: stable/stein

commit 6a5be4ae250b9ff1b8e48947ab80a65827460513
Author: mb <email address hidden>
Date: Fri Mar 29 10:20:58 2019 +0100

    Fix bug preventing forbidden traits from working

    Modifies _clean_empties function to take forbidden traits into account
    in addition to required traits.

    Added unit test test_resources_from_request_spec_flavor_forbidden_trait
    to test that a single forbidden trait doesn't get lost in the
    resources_from_request_spec function.

    Also updated the functional test
    test_flavor_forbidden_traits_based_scheduling to do the right thing.

    Change-Id: I491b10c9c202baae4a37034848147f910a50eebf
    Closes-Bug: #1821824
    (cherry picked from commit c088856c8c08f0ab0746db7c120da494c9dd42d4)