Move pub into sdk/lib/_internal.

sdk/lib/_internal/pub/test/validator/utf8_readme_test.dart

 // 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.
 
 import 'package:scheduled_test/scheduled_test.dart';
 
-import '../../../pub/entrypoint.dart';
-import '../../../pub/validator.dart';
-import '../../../pub/validator/utf8_readme.dart';
+import '../../lib/src/entrypoint.dart';
+import '../../lib/src/validator.dart';
+import '../../lib/src/validator/utf8_readme.dart';
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 Validator utf8Readme(Entrypoint entrypoint) =>
   new Utf8ReadmeValidator(entrypoint);
 
 main() {
   initConfig();
 
@@ skipping 14 matching lines @@
   integration('should consider a package invalid if it has a README with '
       'invalid utf-8', () {
     d.validPackage.create();
 
     d.dir(appPath, [
       d.binaryFile("README", [192])
     ]).create();
     expectValidationWarning(utf8Readme);
   });
 }