pkg/matcher: upgrate tests to test

test/mirror_matchers_test.dart

 // Copyright (c) 2012, 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 matcher.mirror_test;
 
 import 'package:matcher/mirror_matchers.dart';
-import 'package:unittest/unittest.dart' show test;
+import 'package:test/test.dart' show test;
 
 import 'test_utils.dart';
 
 class C {
   var instanceField = 1;
   get instanceGetter => 2;
   static var staticField = 3;
   static get staticGetter => 4;
 }
 
@@ skipping 16 matching lines @@
         'Actual: <Instance of \'C\'> '
         'Which: has a member named "staticField",'
         ' but it is not an instance property');
     shouldFail(c, hasProperty('staticGetter'),
         'Expected: has property "staticGetter" '
         'Actual: <Instance of \'C\'> '
         'Which: has a member named "staticGetter",'
         ' but it is not an instance property');
   });
 }