Update App.tsx

Author: jzuniga206

src/components/App.tsx

@@ -3,7 +3,7 @@ import '../public/styles/style.css';
 import AppContainer from '../containers/AppContainer';
 
 export const App: React.SFC = () => (
-  <div className="app">
+  <div className='app'>
     <div>
       <header style={{ height: '40px', width: '100%' }}>ReacType</header>
       <AppContainer />