Fix chef-solo recipies so we can vagrant up on i

Two things were preventing vagrant from provisioning on 'i':

* Using git protocol when downloading rbenv repo
* Trying to access keyserver.ubuntu.com when installing Node.js from a package

We now use https for rbenv repo and install node from binary, so
you can successfully complete vagrant provisioning even on i.

Total time for new VM build: 11 min 15 s
Merge pull request #3 from thegarage/vagrant-networking

Fix chef-solo recipies so we can vagrant up on i