Remove unused code in App.Cookies

The `removeCookie` function is never called, and the `initialize`
function doesn't do anything. The only functions we use here are
`getCookie` and `saveCookie`.

app/assets/javascripts/application.js

@@ -135,7 +135,6 @@ var initialize_modules = function() {
   App.SendAdminNotificationAlert.initialize();
   App.ModalDownload.initialize();
   App.Settings.initialize();
-  App.Cookies.initialize();
   if ( $('#js-columns-selector').length )
     App.ColumnsSelector.initialize();
   App.BudgetEditAssociations.initialize();