Normally, catching a subprocess.CalledProcessError would suffice
since that exception is thrown when the subprocess exits with a
non-zero code. However this exception is only thrown when using
specific methods like check_output which we no longer use.
This commit now has us explicitly checking the process return code.
Change-Id: I799f92836fba41e718570e2f7affb27f11c26156
Refactoring was done to make more of the methods easier to test.
Existing unit tests were adjusted/simplified and more tests were
added as a result.
Change-Id: I57c334c6a11fa8e12c88bdd0788d63a35cdfd7bc
Added an --offline argument which will prevent Tempest results
from being uploaded to the Refstack server if used.
Change-Id: I40df179288354a6eb7fac1d0ed634d722a780817
Story: https://storyboard.openstack.org/#!/story/190
