heat.stacks.list() returns 'Authentication required' under some circumstances.

[Alexander Koryagin]

Configuration:
MOS 9.1 snapshot #268

During execution of the Heat test suit:
    https://github.com/Mirantis/mos-integration-tests/blob/master/mos_tests/heat/heat_test.py

During step with "heat.stacks.list()"
    https://github.com/Mirantis/mos-integration-tests/blob/master/mos_tests/heat/heat_test.py#L577

We have following error:
    http://paste.openstack.org/show/582366/
    >> HTTPUnauthorized: ERROR: Authentication failed: Authentication required

    https://mirantis.testrail.com/index.php?/tests/view/16132664

The problem that launched alone this test will be passed.
Actions performed manually also will lead to successful execution.

This test only fails when it is launched with all Heat test suit.
Launching this TC with several others can't reproduce issue.

So, I hope snapshot will help to identify root-cause.

[Vitaly Sedelnik (vsedelnik)]

Looks similar to https://bugs.launchpad.net/mos/+bug/1621798, please check again after that one is resolved.