title: How to use scoped locale + path_prefix with Devise?
body: <p>In a Rails 3.2 app I'm using Devise with a <code>path_prefix</code> and localization with scoped routes.</p>
  
  <pre><code>#routes.rb
  MyApp::Application.routes.draw do
    scope "(:locale)", locale: /#{I18n.available_locales.join("|")}/  do
      devise_for :admins,  
        path_prefix: 'administration',
      end
  
     ...other resources
    end
  end
  </code></pre>
  
  <p>While the url for all my other resources is written correctly eg <code>/en/resource/1</code> in the addressbar, Devise paths are passing the locale as a parameter <code>/administration/admins/registrations/login?locale=en</code></p>
  
  <p>How do I encourage Devise to use the format <code>/locale/path_prefix/route</code>?</p>