message: docs: added david-harkness as a contributor
diff: "bug",
  "ideas"
  ]
  + },
  + {
  + "login": "david-harkness",
  + "name": "David Harkness",
  + "avatar_url": "https://avatars0.githubusercontent.com/u/2921?v=4",
  + "profile": "http://rubykata.wordpress.com/",
  + "contributions": [
  + "code"
  + ]
  }
  ]
  }
  