lib/queue.js
function() {
          var promise;
          while (promise = queue.pop()) {
            promise.reject("flush");
          }
          while (promise = running.pop()) {
            promise.reject("flush");
          }
        }
function() {
          var promise;
          while (promise = queue.pop()) {
            promise.reject("flush");
          }
          while (promise = running.pop()) {
            promise.reject("flush");
          }
        }
Flushes the queue. Will reject any remaining promises

@function flush

@return None