Barry Hurley

Fix test incompatibility with Python 3.7 and bump travis versions

1

There was a trailing comma in the repr of `ValueError` exceptions prior to python 3.7. The removal of that is breaking tests under 3.7, so this updates the expected string...

If the control has side effects that cannot easily be isolated from candidates, then it can be useful to run the candidates before the control. It is easier to write...