function didSwipeBackToCancel() {
      var cancelled = false;
      if (options.cancelThreshold !== null && direction !== null) {
        cancelled = (getMaxDistance(direction) - distance) >= options.cancelThreshold;
      }

      return cancelled;
    }
Checks the user has swiped back to cancel.
@return Boolean if <code>cancelThreshold</code> has been set, return true if the cancelThreshold was met, else false.
If no cancelThreshold was set, then we return true.
@inner