Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/integration/server/test_all.dart

 // Copyright (c) 2014, 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.
 
 library test.integration.server.all;
 
-import 'package:unittest/unittest.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../utils.dart';
 import 'get_version_test.dart' as get_version_test;
 import 'set_subscriptions_invalid_service_test.dart'
     as set_subscriptions_invalid_service_test;
 import 'set_subscriptions_test.dart' as set_subscriptions_test;
 import 'shutdown_test.dart' as shutdown_test;
 import 'status_test.dart' as status_test;
 
 /**
  * Utility for manually running all integration tests.
  */
 main() {
   initializeTestEnvironment();
-  group('server', () {
+  defineReflectiveSuite(() {
     get_version_test.main();
     set_subscriptions_test.main();
     set_subscriptions_invalid_service_test.main();
     shutdown_test.main();
     status_test.main();
-  });
+  }, name: 'server');
 }