Rename "tests" directories under /pkg to the singular "test"

pkg/i18n/tests/intl_test.dart

Index: pkg/i18n/tests/intl_test.dart
===================================================================
--- pkg/i18n/tests/intl_test.dart	(revision 10770)
+++ pkg/i18n/tests/intl_test.dart	(working copy)
@@ -1,15 +0,0 @@
-// 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('intl_test');
-
-#import('../intl.dart');
-#import('../../../pkg/unittest/unittest.dart');
-
-main() {
-  test('Set locale', (){
-    var de = new Intl('de_DE');
-    expect(de.locale, equals('de'));
-  });
-}