Modernize the package's style.

lib/src/stream_splitter.dart

Index: lib/src/stream_splitter.dart
diff --git a/lib/src/stream_splitter.dart b/lib/src/stream_splitter.dart
index ac401a7b1e26b65893e55624e52ea9dee3d08bdb..ec648aad1c42fd58c265a97a99f6d4149f4fc110 100644
--- a/lib/src/stream_splitter.dart
+++ b/lib/src/stream_splitter.dart
@@ -2,12 +2,10 @@
 // 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 async.stream_splitter;
-
 import 'dart:async';
 
-import '../result.dart';
 import 'future_group.dart';
+import 'result.dart';
 
 /// A class that splits a single source stream into an arbitrary number of
 /// (single-subscription) streams (called "branch") that emit the same events.