For the initial setup of this page to work, you need to have Ruby, RubyGems and Bundler installed.
Ruby comes preinstalled on OSX, so if you're using a Mac you're good to go! If you're using another OS, please check the ruby-lang.org installation page!
To install RubyGems, go to the rubygems.com download page and download the latest version for your OS!
With RubyGems installed, enter sudo gem install bundler into your terminal and bundler will be installed!