RoR installation on Ubuntu 14.04

1. sudo apt-get install rbenv
2. rbenv install [Ruby version]
   This step takes a while...It took 5 minutes on my i7 machine
3. add system variable to your startup script
   ~/.bashrc in Ubuntu
   add these two lines

export PATH="$HOME/.rbenv/bin:$PATH"

eval "$(rbenv init -)"

That's it. Easier than I expected....