Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/analysis/notification_analysis_options_test.dart

 // Copyright (c) 2015, 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.analysis.notification_analysis_options_test;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/services/lint.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../analysis_abstract.dart';
 import '../mocks.dart';
 import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(NewAnalysisOptionsFileNotificationTest);
-  defineReflectiveTests(OldAnalysisOptionsFileNotificationTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(NewAnalysisOptionsFileNotificationTest);
+    defineReflectiveTests(OldAnalysisOptionsFileNotificationTest);
+  });
 }
 
 abstract class AnalysisOptionsFileNotificationTest
     extends AbstractAnalysisTest {
   Map<String, List<AnalysisError>> filesErrors = {};
 
   final testSource = '''
 main() {
   var x = '';
   int y = x; // Not assignable in strong-mode
@@ skipping 279 matching lines @@
 class NewAnalysisOptionsFileNotificationTest
     extends AnalysisOptionsFileNotificationTest {
   String get optionsFilePath => '$projectPath/analysis_options.yaml';
 }
 
 @reflectiveTest
 class OldAnalysisOptionsFileNotificationTest
     extends AnalysisOptionsFileNotificationTest {
   String get optionsFilePath => '$projectPath/.analysis_options';
 }