fixup! Fix some small review issues
Update version
Use a simpler way of closing windows between tests.
Reduce the amount of work we do computing command line arguments.
Remove retry count in executormarionette as TestRunnerManager logs it

Also corrects some capitalization of the word "Marionette", and
logs the message of any exceptions.

Conflicts:
	wptrunner/executors/executormarionette.py