Update paver bok_choy (test) commands to reflect new default vars.

@clytwynec @nasthagiri 

This takes into account recent changes for how bok-choy commands are composed in paver. (Should also bring Jenkins back to green.)


When nothing is passed to the paver command (e.g., `paver test_bokchoy`), None is being sent in. 

That's how it's running now...I just took what it is producing as-is...