WIP: Step 6 unit tests
WIP: Step 6 unit tests

weidnem/IntroPython2016,weidnem/IntroPython2016,UWPCE-PythonCert/IntroPython2016,UWPCE-PythonCert/IntroPython2016,weidnem/IntroPython2016,UWPCE-PythonCert/IntroPython2016