more work on establishing credentials

src/lib/queue.js

@@ -11,8 +11,8 @@ export default function() {
 
         put(item) {
             this.items.push(item);
-            if (this.resolvers.length > 0) {
-                let resolver = this.resolvers.shift();
+            let resolver = this.resolvers.shift();
+            if (resolver) {
                 resolver();
             }
         },