Removes per test testr timeout

Because testr run tests in parallel and we use fake driver of
oslo.messaging to make unittests and this one use time.sleep() monkey
patched by eventlet, a test can take a lot of time, just because
eventlet have decided to run other tests before instead of finish the
started one.

So, just remove the per test testr timeout, like we have before.

Change-Id: I26f14937a16b23428f55fc7f42b4066b398c06a8
Closes-bug: #1323524
Merge "Removes per test testr timeout"