Added vagrant support

This should make contributions and testing a bit easier.

It handles creating a vagrant guest with all the necessary dev libraries, then testing is built into a single Makefile command. There's also some basic status tests to reduce overheads on Vagrant commands (e.g. vagrant up, which can take several seconds alone).

This could be improved at a later date to also include some automatic service repair (e.g. if Redis dies), but for now this will get the job done nicely. I've been using this for the PRs I sent today, and it worked beautifully.