create more robust selenium tests

[hamilton]

I'm a mere data scientist; while I can string together a useful Selenium workflow, this particular project demands a much deeper knowledge of exactly how Selenium works. I am not 100% sure I understand how Selenium maintains focus of the browser, window, & tab. While this doesn't matter quite as much for a web-based end-to-end test, it's crucial for this project, since events fire when the browser loses focus.