using get_or_create when testing for group membership

@goranche I don't know. We could then (re)write the test for all of the Django, if we adopt this mindset. Not to mention, this is a "bolognese" at it's best :). 
I am not exactly sure what is the problem with South? Is this needed because the migrations arent runinig? I am intrigued about pytest having this bug, what exactly is it?