message: [improvement] Picker: add test case
diff: @@ -181,3 +181,14 @@ test('click column\'s item', () => {
  wrapper.findAll('.van-picker-column__item').at(3).trigger('click');
  expect(wrapper.emitted('change')[0][1]).toEqual(columns[1]);
  });
  +
  +test('toolbar-position prop', () => {
  + const wrapper = mount(Picker, {
  + propsData: {
  + showToolbar: true,
  + toolbarPosition: 'bottom'
  + }
  + });
  +
  + expect(wrapper).toMatchSnapshot();
  +});
  