Switch polymer's build.dart to use the new linter. This CL does the following

pkg/polymer/build.dart

Index: pkg/polymer/build.dart
diff --git a/pkg/polymer/build.dart b/pkg/polymer/build.dart
deleted file mode 100755
index 4599716cec05f40b1c5221ee686a4fc2346f138a..0000000000000000000000000000000000000000
--- a/pkg/polymer/build.dart
+++ /dev/null
@@ -1,15 +0,0 @@
-#!/usr/bin/env 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.
-
-/** Build logic that lets the Dart editor build examples in the background. */
-library build;
-import 'package:polymer/component_build.dart';
-import 'dart:io';
-
-void main() {
-  build(new Options().arguments, [
-    'example/component/news/web/index.html',
-    'example/scoped_style/index.html']);
-}