code: function offEvent(gesture, handler){
        var gestures = gesture.split(' ');
        for(var t=0; t<gestures.length; t++) {
          this.element.removeEventListener(gestures[t], handler, false);
        }
        return this;
      }
docs: unbind events to the instance
  @param   {String}      gesture
  @param   {Function}    handler
  @returns {ionic.Gestures.Instance}