Fixed challenge ordering

controllers/resources.js

@@ -192,6 +192,15 @@ module.exports = {
 
     allBonfireIds: function() {
         return bonfires.map(function(elem) {
+            return {
+                _id: elem._id,
+                difficulty: elem.difficulty
+            }
+        })
+        .sort(function(a, b) {
+            return a.difficulty - b.difficulty;
+        })
+        .map(function(elem) {
             return elem._id;
         })
     }