gitio: 1.0.0 - Shorten a github.com URL to a git.io URL

Usage: gitio URL [code]

Examples:
  $ gitio https://gist.github.com/ryansobol/7214372
  http://git.io/EgwCBg

  $ gitio https://github.com/ryansobol ryansobol
  http://git.io/ryansobol