title: componentDidCatch is not getting called when there is an error in promise
body: <p>As per the new <a href="https://reactjs.org/blog/2017/07/26/error-handling-in-react-16.html" rel="nofollow noreferrer">react 16 release doc</a> it says</p>
  
  <p><strong>"React 16 prints all errors that occurred during rendering to the console in development, even if the application accidentally swallows them."</strong></p>
  
  <p>I have a <strong>Parent</strong> component and a <strong>Child</strong> component. I have triggered an error in then block of promise. But it will call catch method of the promise, componentDidCatch of parent is not getting called. I am not sure whether this the expected behaviour.</p>
  
  <p>Here is the jsfiddle <a href="https://jsfiddle.net/john1jan/Luktwrdm/14/" rel="nofollow noreferrer">https://jsfiddle.net/john1jan/Luktwrdm/14/</a></p>
  
  <pre><code>class Parent extends React.Component {  
    constructor(props){
      super(props);
      this.state={hasError:false}
    }
  
    render() {
      if(this.state.hasError){
        return &lt;div&gt;Something went wrong&lt;/div&gt;
      }
  
      return (
        &lt;div&gt;
          &lt;h1&gt;I am parent&lt;/h1&gt;
          &lt;Child&gt;&lt;/Child&gt;
        &lt;/div&gt;
      );
    }
    componentDidCatch(error,errorInfo){
      this.setState({
        hasError:true
      })
    }
  }
  
  class Child extends React.Component {
  
    render() {
      return (
        &lt;div&gt;
          &lt;h1&gt;I am child&lt;/h1&gt;
        &lt;/div&gt;
      );
    }
  
    componentDidMount(){
      fetch("https://jsonplaceholder.typicode.com/posts").then((response) =&gt; {
        throw new Error("I am the error in promise");
      }).catch((error)=&gt;{
        console.log("Error caught in catch",error);
      })
      ;
    }
  }
  
  ReactDOM.render(&lt;Parent name="world"/&gt;, 
  document.getElementById('container'));
  </code></pre>