Get rid of all the library tags.

test/transformer/configuration/configuration_defaults_to_empty_map_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
-
 import 'dart:convert';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 import '../../serve/utils.dart';
 
 final transformer = """
 import 'dart:async';
 import 'dart:convert';
 
@@ skipping 33 matching lines @@
          d.file("foo.txt", "foo")
        ])
      ]).create();
 
      pubGet();
      pubServe();
      requestShouldSucceed("foo.json", JSON.encode({}));
      endPubServe();
    });
 }