[rackspace|compute_v2] compute_v2 tests were failing because the flavor used in the tests was too small for the image selected. I updating tests to use the an Ubuntu image in hopes of making the tests less brittle.
Merge branch 'master' of github.com:fog/fog into test_fix
Merge pull request #1609 from rackspace/test_fix

[Rackspace|Compute_v2] Improving tests