initialize dropdown after turbolink request

app/assets/javascripts/application.js

@@ -30,12 +30,11 @@ var initialize_modules = function() {
   App.Votes.initialize();
   App.Tags.initialize();
   App.Stats.initialize();
+  App.Dropdown.initialize();
   App.LocationChanger.initialize();
 };
 
 $(function(){
-  $(document).foundation();
-
   $(document).ready(initialize_modules);
   $(document).on('page:load', initialize_modules);
   $(document).on('ajax:complete', initialize_modules);