using unittest via package import

tests/html/uri_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import '../../pkg/unittest/lib/unittest.dart';
-import '../../pkg/unittest/lib/html_config.dart';
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_config.dart';
 import 'dart:html';
 
 main() {
   useHtmlConfiguration();
 
   test('Uri.base', () {
     expect(Uri.base.scheme, "http");
     expect(Uri.base.toString(), window.location.href);
   });
 }