Update versions: VM (2014-05), Vagrant (1.6.1), VirtualBox (4.3.10), ruby (2.0.0p451)

Ubuntu 14.04!

The final box file referred to here is not built yet. Please download this RC and test:

http://downloads.railsbridge.org/railsbridgevm-2014-05-rc1.box

with the new Virtualbox/Vagrant versions.