message: [Improvement] DatetimePicker: add new type & show-toolbar prop
diff: @@ -35,6 +35,17 @@ describe('DatetimePicker', () => {
  expect(wrapper.vm.innerValue.getTime()).to.equal(testDate.getTime());
  });
  + it('create a date-year-month', () => {
  + wrapper = mount(DatetimePicker, {
  + attachToDocument: true,
  + propsData: {
  + type: 'date-year-month',
  + value: testDate
  + }
  + });
  + expect(wrapper.vm.innerValue.getTime()).to.equal(testDate.getTime());
  + });
  +
  it('create a datetime picker', () => {
  wrapper = mount(DatetimePicker, {
  attachToDocument: true,
  @@ -93,6 +104,31 @@ describe('DatetimePicker', () => {
  }, 10);
  });
  + it('drag date-year-month picker', (done) => {
  + wrapper = mount(DatetimePicker, {
  + attachToDocument: true,
  + propsData: {
  + type: 'date-year-month',
  + value: testDate,
  + minDate,
  + maxDate
  + }
  + });
  +
  + setTimeout(() => {
  + const [year, month] = wrapper.find('.van-picker-column ul');
  + dragHelper(year, 0, -50);
  + dragHelper(month, 0, -50);
  + setTimeout(() => {
  + const newYear = wrapper.vm.innerValue.getFullYear();
  + const newMonth = wrapper.vm.innerValue.getMonth() + 1;
  + expect(newYear).to.equal(2018);
  + expect(newMonth).to.equal(4);
  + done();
  + }, 10);
  + }, 10);
  + });
  +
  it('drag datetime picker', (done) => {
  wrapper = mount(DatetimePicker, {
  attachToDocument: true,
  