Added unicorn to gem file.
Some changes/fixes to login.

modified:   Gemfile
modified:   Gemfile.lock
modified:   app/assets/javascripts/angular/controllers/home.js
modified:   app/assets/javascripts/angular/controllers/users.js
modified:   app/assets/javascripts/angular/directives/directives.js
modified:   app/assets/javascripts/angular/services/services.js
modified:   app/assets/javascripts/app.js
modified:   app/assets/templates/home.html
modified:   app/assets/templates/user_details.html
modified:   app/assets/templates/users_list.html
modified:   app/controllers/api/callbacks_controller.rb
modified:   app/models/tag.rb
modified:   app/views/layouts/application.html.erb
modified:   db/development_seeds.rb
modified:   lib/assets/javascripts/angular-http-auth.js
modified:   spec/controllers/tags_controller_spec.rb
modified:   spec/support/api_examples_update.rb