[Enhancement] Group widget messages by users (#367)

* Remove thumbnail

* Show grouped messages

config/environments/test.rb

@@ -21,6 +21,7 @@ Rails.application.configure do
     'Cache-Control' => "public, max-age=#{1.hour.to_i}"
   }
   config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }
+  Rails.application.routes.default_url_options = { host: 'localhost', port: 3000 }
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true