componentWillMount() {
    fetch(countries)
      .then(data => data.json())
      .then(data => {
         // call fetch cities by constructing a "dummy" event.
         const first = json.results[0]
         const evt = {target: {value: first.code} }
         fetchCities(evt)
         // pass the data on
         return data
      })
      .then(json => this.setState({ countries: json.results}))
  }



  fetchCities = (evt) => {
    const countryCode = evt.target.value
    fetch(cities + "?country=" + countryCode)
    .then(data => data.json())
    .then(cities => {
      // construct a "dummy event and then call fetchAir
      const first = cities.results[0]
      const evt = {target: {value: first.city}}
      fetchAir(evt)
      // pass the data on
      return cities
    })
    .then(cities => this.setState({cities: cities.results}))

  }



  fetchAir = (evt) => {
      const Air = evt.target.value
      fetch(latest +"?city="+ Air)
      .then(data => data.json())
      .then(data => this.setState({latest: data.results}))
  }