Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/search/hierarchy_test.dart

Index: pkg/analysis_server/test/services/search/hierarchy_test.dart
diff --git a/pkg/analysis_server/test/services/search/hierarchy_test.dart b/pkg/analysis_server/test/services/search/hierarchy_test.dart
index 802f351b8ad6acb193a2200431af1ca783310b5d..18c034f365728f2fab3d5f568314c8d61f0e5c67 100644
--- a/pkg/analysis_server/test/services/search/hierarchy_test.dart
+++ b/pkg/analysis_server/test/services/search/hierarchy_test.dart
@@ -10,15 +10,17 @@ import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/search/hierarchy.dart';
 import 'package:analysis_server/src/services/search/search_engine_internal.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../../abstract_single_unit.dart';
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(HierarchyTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(HierarchyTest);
+  });
 }
 
 @reflectiveTest