Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/completion/dart/optype_test.dart

Index: pkg/analysis_server/test/services/completion/dart/optype_test.dart
diff --git a/pkg/analysis_server/test/services/completion/dart/optype_test.dart b/pkg/analysis_server/test/services/completion/dart/optype_test.dart
index 2fe206b08c22a618a4dec3078ba5190ada985ec7..3258cc2264a99f7c9a2d91446a4d78085584327e 100644
--- a/pkg/analysis_server/test/services/completion/dart/optype_test.dart
+++ b/pkg/analysis_server/test/services/completion/dart/optype_test.dart
@@ -11,15 +11,17 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:plugin/manager.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../../../abstract_context.dart';
 import '../../../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(OpTypeTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(OpTypeTest);
+  });
 }
 
 @reflectiveTest