fix the imports

Author: nturgut

packages/e2e/example/test_driver/example_e2e_web_test.dart

@@ -4,6 +4,7 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:flutter_driver/flutter_driver.dart';
+import 'package:test/test.dart';
 
 Future<void> main() async {
   final FlutterDriver driver = await FlutterDriver.connect();