Use travis container-based infrastructure.
Use travis container-based infrastructure.

See https://docs.travis-ci.com/user/migrating-from-legacy/.

pmdarrow/locust,bugsduggan/locust,mbeacom/locust,santiavenda2/locust,pan1cz/locust,pan1cz/locust,heyman/locust,bugsduggan/locust,pmdarrow/locust,fordhurley/locust,cgoldberg/locust,locustio/locust,locustio/locust,santiavenda2/locust,pmdarrow/locust,locustio/locust,santiavenda2/locust,fordhurley/locust,cgoldberg/locust,mbeacom/locust,locustio/locust,TZer0/locust,bugsduggan/locust,fordhurley/locust,cgoldberg/locust,TZer0/locust,pan1cz/locust,mbeacom/locust,TZer0/locust,mbeacom/locust