Minor fixes.

Author: crsanti

samples/react/es6/00 SimpleForm/src/index.jsx

@@ -1,8 +1,8 @@
 import React from 'react';
-import { render } from 'react-dom';
+import ReactDOM from 'react-dom';
 import App from './components/app';
 
-render(
+ReactDOM.render(
   <App />,
   document.getElementById('root'),
 );

samples/react/es6/01 SignupForm/src/index.jsx

@@ -1,8 +1,8 @@
 import React from 'react';
-import { render } from 'react-dom';
+import ReactDOM from 'react-dom';
 import App from './components/app';
 
-render(
+ReactDOM.render(
   <App />,
   document.getElementById('root'),
 );

samples/react/es6/02 QuizForm/src/index.jsx

@@ -1,8 +1,8 @@
 import React from 'react';
-import {render} from 'react-dom';
+import ReactDOM from 'react-dom';
 import App from './components/app';
 
-render(
+ReactDOM.render(
   <App />,
   document.getElementById('root'),
 );