remove unused imports

Author: denrase

flutter/example/integration_test/integration_test.dart

@@ -1,6 +1,3 @@
-import 'dart:io';
-
-import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';