Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/src/watch_manager_test.dart

Index: pkg/analysis_server/test/src/watch_manager_test.dart
diff --git a/pkg/analysis_server/test/src/watch_manager_test.dart b/pkg/analysis_server/test/src/watch_manager_test.dart
index 99b76fcb20c0f9f65cfbec328c33017d9e011b8e..783272cf36ae808bda38b278dcd060b02bc92f24 100644
--- a/pkg/analysis_server/test/src/watch_manager_test.dart
+++ b/pkg/analysis_server/test/src/watch_manager_test.dart
@@ -9,8 +9,8 @@ import 'dart:async';
 import 'package:analysis_server/src/watch_manager.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 import 'package:watcher/watcher.dart';
 
 import '../mocks.dart';
@@ -18,8 +18,10 @@ import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(WatchManagerTest);
-  defineReflectiveTests(WatchNodeTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(WatchManagerTest);
+    defineReflectiveTests(WatchNodeTest);
+  });
 }
 
 /**