Speed up ironic tests

This change speeds up ironic tests by 60% by:
* Mocking eventlet.greenthread.sleep in a handful of tests
* Changing a time.sleep(2) to time.sleep(0.2) in a test where
  time.sleep is used intentionally for testing

Change-Id: I0cd2ae06549844ec3b76e7c91e1f49665ebc9717
Merge "Speed up ironic tests"