Stories reply and upvote redirect to signin when user isn't signed in.

Redirects user back to story after signing in.

public/js/main.js

@@ -135,6 +135,10 @@ $(document).ready(function() {
     });
 
     var upvoteHandler = function () {
+        if (typeof user == "undefined" || !user) {
+            window.location.href = '/signin';
+            return;
+        }
         var _id = storyId;
         $('#upvote').unbind('click');
         var alreadyUpvoted = false;