Require reproducible tests and even a test environment

[ollytom]

To run and test this icingaweb2 module, we need to install the module into some sort
of reproducible, consistent environment. What does/should that environment be?

We've got so many tools available now to answer these types of questions, let's just JFDI.

I see a directory 'regress' in lots of unix-like OS tools, which contain a bunch of little test programs. In there, we'll also put in a Vagrantfile for use with vagrant(1) because, you know... devops.