One of the tests would output stderr and it would not be captured by tox
resulting in output like this http://paste.openstack.org/show/616128/
The tests are working fine but that output gives a false impression to the
developer that something is wrong
I captured the stderr during that test so that would not show.
Change-Id: I7f76da0cb1a57280848d7d831e2a686e4ec5c81a