updating test and removing deprecated selenium driver

Author: Protik Biswas

Example/__tests__/App-test.js

@@ -7,8 +7,9 @@ import React from 'react';
 import App from '../App';
 
 // Note: test renderer must be required after react-native.
-import renderer from 'react-test-renderer';
+import { createLegacyRoot } from 'react-test-renderer';
 
 it('renders correctly', () => {
-  renderer.create(<App />);
+  const root = createLegacyRoot(<App />);
+  root.unmount();
 });