Using Tox and PyTest with OpenFaaS

I think it is an uncontroversial statement to say testing is important in software development. Writing tests may not always be fun, but nothing is a sweet as that moment when a unit test catches a bug before you deploy. In OpenFaaS we have tons of tests in each project, even the certifier itself runs a short suite of end-to-end tests. But, not all of our function templates have first class testing support.