Upgrade to the new test runner.

test/server/batch_test.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 json_rpc_2.test.server.batch_test;
 
 import 'dart:convert';
 
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 import 'package:json_rpc_2/error_code.dart' as error_code;
 import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
 
 import 'utils.dart';
 
 void main() {
   var controller;
   setUp(() {
     controller = new ServerController();
     controller.server
@@ skipping 65 matching lines @@
       'jsonrpc': '2.0',
       'id': null,
       'error': {
         'code': error_code.INVALID_REQUEST,
         'message': 'Request must be an Array or an Object.',
         'data': {'request': [{'jsonrpc': '2.0', 'method': 'foo', 'id': 1}]}
       }
     }])));
   });
 }