function select (index, canSkipClick) {
    if (!locked) ctrl.focusIndex = ctrl.selectedIndex = index;
    // skip the click event if noSelectClick is enabled
    if (canSkipClick && ctrl.noSelectClick) return;
    // nextTick is required to prevent errors in user-defined click events
    $mdUtil.nextTick(function () {
      ctrl.tabs[ index ].element.triggerHandler('click');
    }, false);
  }
Update the selected index. Triggers a click event on the original `md-tab` element in order
to fire user-added click events if canSkipClick or `md-no-select-click` are false.
@param index
@param canSkipClick Optionally allow not firing the click event if `md-no-select-click` is also true.