Add a throwaway development/testing environment

Paraphrasing [Why Vagrant](http://docs.vagrantup.com/v2/why-vagrant/):

> Using Vagrant and chef-solo will allow us to run the same code in the same environment as other l1j-en developers, against the same versions of Java and MySQL without modifying our host environments.

This PR adds a Vagrant box, provisioned by chef-solo, for, hopefully, all future l1j-en development to be done in.

## Ready, set…

You'll need to install Vagrant, which will install the vagrant gem. You can download the Vagrant installer for your host environment from [here](http://www.vagrantup.com/downloads).

Next you'll need to `gem install librarian-chef`. librarian-chef is a "bundler" (a dependency manager) for chef cookbooks and will download the chef cookbooks that are needed to provision the box.

## Go!

First let's download, boot, and provision the box:

```
$ librarian-chef update
$ vagrant up
```

Now let's run l1j-en:

```
$ vagrant ssh
$ cd /vagrant
$ bash serverstart.sh
```