Update installation doc with supported py versions (#547)
Update installation doc with supported py versions (#547)


TZer0/locust,locustio/locust,mbeacom/locust,heyman/locust,pan1cz/locust,bugsduggan/locust,fordhurley/locust,pan1cz/locust,pan1cz/locust,TZer0/locust,locustio/locust,mbeacom/locust,mbeacom/locust,mbeacom/locust,TZer0/locust,fordhurley/locust,bugsduggan/locust,locustio/locust,locustio/locust,fordhurley/locust,bugsduggan/locust