https://github.com/thoughtbot/rcm
https://medium.com/@webprolific/getting-started-with-dotfiles-43c3602fd789#.vqvq9dgfs
http://www.joshstaiger.org/archives/2005/07/bash_profile_vs.html
http://lapwinglabs.com/blog/hacker-guide-to-setting-up-your-mac