add datepicker

import {Component} from '@angular/core';
import {StyleSheet} from 'react-native';

@Component({
  selector: 'hello-app',
  host: {position: 'abolute', top: '0', left: '0', bottom: '0', right: '0'},
  template: `
  <View>
    <DatePicker></DatePicker>
  </View>`
  })
  export class HelloApp {
  styles: any;
  constructor() {
    this.styles = StyleSheet.create({
    });
  }
}