chore: Fixing review comments on Dart transformers

See https://codereview.chromium.org/927373004/

Closes #705

modules/angular2/test/transform/common.dart

@@ -1,7 +1,7 @@
 // Copyright (c) 2013, 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 initialize.test.build.common;
+library angular2.test.transform;
 
 // TODO(kegluneq): Remove this and use the actual Directive def'n.
 // Simple mock of Directive.

modules/angular2/test/transform/transform_test.dart

@@ -1,4 +1,4 @@
-library angular2.test;
+library angular2.test.transform;
 
 import 'dart:io';
 import 'package:barback/barback.dart';