Fixed linting errors

Author: Niels de Bruin

Diff for: packages/react-scripts/template/src/App.tsx

@@ -4,7 +4,7 @@ import './App.css';
 import logo from './logo.svg';
 
 class App extends React.Component {
-  render() {
+  public render() {
     return (
       <div className="App">
         <header className="App-header">

Diff for: packages/react-scripts/template/src/index.tsx

@@ -1,8 +1,8 @@
 import * as React from 'react';
 import * as ReactDOM from 'react-dom';
 import App from './App';
-import registerServiceWorker from './registerServiceWorker';
 import './index.css';
+import registerServiceWorker from './registerServiceWorker';
 
 ReactDOM.render(
   <App />,