While running the tests with the latest tox I was getting the following error message:
```
failed with pass_env values cannot contain whitespace, use comma to have multiple values in a single line'
```
That error is happening because of the passenv declaration. This patch is proposing a fix for that.
Besides the `tox` issue, we also needed to create a patch for the use of virtual env inside DevStack.
This patches presents a solution to run tests using the virtual env of DevStack.
Change-Id: Id8249ebb15d4047dcc6181908eae66eb39722863
244f229af7