title: How do you map the payload in angular 5 using the HttpClient and redux
body: <p>How would I do the equivalent of this call in my service using HttpClient instead of Http?  HttpClient doesn't the map() call.</p>
  
  <pre><code>loadObservations() {
    this.http.get(`${BASE_URL}${1000}`)
      .map(res =&gt; res.json())
      .map(payload =&gt; ({ type: 'ADD_OBSERVATIONS', payload }))
      .subscribe(action =&gt; this.store.dispatch(action));
  }
  </code></pre>