Switch 'analyzer' to 'package:test' and test_reflective_loader ^0.1.0.

pkg/analyzer/test/source/config_test.dart

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/source/config.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 import 'package:yaml/yaml.dart';
 
 main() {
   group('Analysis Config', () {
     test('parseConfigSource', () {
       String source = r'''
 analyzer:
   configuration: google/strict
 ''';
       YamlMap options = loadYamlNode(source);
       AnalysisConfigurationDescriptor descriptor =
           new AnalysisConfigurationDescriptor.fromAnalyzerOptions(
               options['analyzer']);
       expect(descriptor.package, 'google');
       expect(descriptor.pragma, 'strict');
     });
   });
 }