No need to manually cancel all promises.

Rejection should be propagated.

lib/rsvp/queue.js

@@ -23,7 +23,7 @@ var Queue = function() {
   }
 
   function canceller() {
-    for (var i = 0; i < promise_list.length; i++) {
+    for (var i = 0; i < 2; i++) {
       promise_list[i].cancel();
     }
   }