This test verifies that we are able to remove credentials, by checking that we get an authenticaton.
challenge for a path we normally would not get a challenge for, after having removed all credentials.
The first frame's path is /loading/resources/protected-resource.py, and we should get a challenge for it.
It will be authorized with first/first-pw.
The second frame's path is identical to the first frame, and we should get a challenge for it, because credentials have been deleted.
It will be authorized with second/second-pw.