added gems and using
gem 'therubyracer', :platforms => :ruby javaScript Interpreter for Server Side

# project specif gems
gem 'devise'                # Benutzermanagement
gem 'paper_trail', '~> 2'   # Wird von Paperclip (s.u.) benötigt
gem 'paperclip', '~> 3.0'   # Versionierung
gem 'ckeditor'              # WYSIWYG-Editor