Open Stack

A patch was submitted with some new tests of this api 
https://review.openstack.org/#/c/49778/. I gave a -1 because if a 
negative test to shutdown a host fails, a compute node will be shutdown. 
The author thinks this test should be part of tempest. My issue was that 
we should not have tempest tests for apis that:

1. May corrupt the underlying system (that is part of the reason we 
moved whitebox out)
2. Can have only negative tests because positive ones could prevent 
other tests from executing

Thoughts?

  -David