[FLOC-1070] Acceptance test runner.

The tutorial Vagrantfile hard-codes the version of the tutorial base box, which means that it needs to be edited to run tests against other versions.

This provides a new Vagrantfile, and a test runner that invokes it. Hopefully, the new runner should also be able to deal with cloud VMs eventually too.
I like how you've simplified this step, but it doesn't work for me.

```
(1070)(acceptance-runner-FLOC-1070 =)[~/.../HybridLogic/flocker]$ vagrant box add http://build.staging.clusterhq.com/results/vagrant/acceptance-runner-FLOC-1070/flocker-tutorial.json
A name is required when adding a box file directly. Please pass
the `--name` parameter to `vagrant box add`. See
`vagrant box add -h` for more help.
```
```
(1070)(acceptance-runner-FLOC-1070 =)[~/.../HybridLogic/flocker]$ vagrant --version
Vagrant 1.6.5
```