Vagrant router integration and updated readme

This PR addresses https://trello.com/c/cQf9jDeE/555-3-provide-readme-and-vagrant-setup-for-routing.

Features:

1. readme detailing full router setup
2. integration with vagrant single machine environment
3. integration with vagrant clustered machine environment where the router is placed on a new, unregistered minion
How does this sound?  

1. Move provision-router.sh to hack/install-router.sh (no other changes necessary to this file)
2. Remove provision-router.sh from Vagrantfile
3. Update readme to reflect running `hack/install-router.sh {master ip}` after cluster is up and running