[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.
Actually, it is reasonable to want to run the `Vagrantfile`. (Perhaps to run `vagrant destroy`). So forcing it to be passed won't work. I did change the default to just not pass a version.