Authenticate to draugiem.lv and frype.com and others.

@example Basic Rails Usage

 Add this to config/initializers/omniauth.rb

   Rails.application.config.middleware.use OmniAuth::Builder do
     provider :draugiem, 'App id', 'API Key'
   end

@example Basic Rack example

 use Rack::Session::Cookie
 use OmniAuth::Strategies::Draugiem, 'App id', 'API Key'