new vagrant init

New Ubuntu Ruby on Rails vagrant box based on: https://vagrantcloud.com/boxer/ubuntu-14.04-ruby. The box was setup in a standalone directory using the vagrant init on the page and then the VagrantFile was copied to here to the repo
add setup and usage instructions

Usage instructions cover two scenarios: when setting up a vagrant box to create a new rails project inside of, and setting up a vagrant box inside an existing rails application