Bubble the error to top if we don't handle it in Ember.Route

A proper thing to do when an error is not handled is to bubble it up
rather than using throw (which we were using before this commit).

assets/scripts/app/routes.coffee

@@ -20,7 +20,7 @@ Ember.Route.reopen
         authController.set('redirected', true)
         @transitionTo('auth')
       else
-        throw(error)
+        return true
 
     renderNoOwnedRepos: ->
       @render('no_owned_repos', outlet: 'main')