Fix up test_qpid to use BaseTestCase.

While we're in there, simplify its use of fixtures.

Part of blueprint grizzly-testtools.

Change-Id: I7ef05cc9c191aab1959a31770f905f34447e64ea
Replaced direct usage of stubout with BaseTestCase.

BaseTestCase properly hooks stubout into fixtures. Just use that.

Part of blueprint grizzly-testtools.

Change-Id: I4bf6b92b9b16d051d8c6ecaf52cf70925848ed8c
Merge "Fix up test_qpid to use BaseTestCase."
Merge "Replaced direct usage of stubout with BaseTestCase."