Alert users when gists are being fetched

Fixes #20

 * Add unicorn gem
 * Add foreman gem
 * Add a Profile with web process which uses unicorn
 * Add unicorn config
 * Force all logging through STDOUT for unicorn
 * Remove ProfileController before_filter which fetchs gists
 * Add route for TagsController#index
 * Implement TagsController#index to list the signed in users tags
   * Only respond to JavaScript requests
   * Before the index action, refresh the signed in users gists
  TagsController#index does not render the layout
 * When rendering ProfileController#show, only render a info alert telling the user their gists are being fetched from GitHub
 * When ProfileController#show DOM fully loaded, get the signed in users tags from TagsController#index and inject the tags into the DOM
   * Add ajax spinner to visually indicate gists are still being fetched
 * Add ProfileController CoffeeScript file
 * Add spec for profile fetching notice
 * Add poltergeist gem and downgrade capybara for poltergeist
 * In spec helper, set poltergeist as Capybara javascript driver
 * Remove before each from auth github spec
 * Remove ProfileController spec which tests for list of tags
 * Add spec feature to test JavaScript loading of tags
 * Upgrading rails to 3.2.10
 * Link profile username back to profile