fixed imports

src/index.js

@@ -4,7 +4,7 @@ import App from './App';
 import * as serviceWorker from './serviceWorker';
 import { createBrowserHistory } from 'history';
 import { CssBaseline } from '@material-ui/core';
-import { BrowserRouter as Router} from 'react-router-dom';
+import { BrowserRouter as Router } from 'react-router-dom';
 
 export const history = createBrowserHistory({
   basename: process.env.PUBLIC_URL