unit tests fail based on wall clock time

[Brant Knudson]

We've got a lot of tests that depend on how long the test takes to run. Tests can take a long time just because you have a slow or overloaded system, or maybe you're trying to step through it with the debugger.

The tests that fail generally don't care about the time and aren't attempting to verify performance, but still require that the test run quickly enough.

Tests shouldn't depend on the wall clock time, just like they shouldn't depend on any external factors.

Here's an example of a failing test:

keystone.tests.unit.test_auth.AuthWithRemoteUser.test_scoped_remote_authn
-------------------------------------------------------------------------

Captured traceback:
~~~~~~~~~~~~~~~~~~~
    Traceback (most recent call last):
      File "keystone/tests/unit/test_auth.py", line 741, in test_scoped_remote_authn
        enforce_audit_ids=False)
      File "keystone/tests/unit/test_auth.py", line 104, in assertEqualTokens
        timeutils.parse_isotime(b['access']['token']['expires']))
      File "keystone/tests/unit/core.py", line 521, in assertCloseEnoughForGovernmentWork
        self.assertTrue(abs(a - b).seconds <= delta, msg)
      File "/home/jenkins/workspace/keystone/.tox/py27/local/lib/python2.7/site-packages/unittest2/case.py", line 678, in assertTrue
        raise self.failureException(msg)
    AssertionError: False is not true : 2015-06-11 13:34:46+00:00 != 2015-06-11 13:34:50+00:00 within 3 delta

It took 4 seconds rather than 3.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/190790