Update the pubspec's homepage link.

pkgs/source_maps/pubspec.yaml

diff --git a/pkgs/source_maps/pubspec.yaml b/pkgs/source_maps/pubspec.yaml
index 2751034..1d94c32 100644
--- a/pkgs/source_maps/pubspec.yaml
+++ b/pkgs/source_maps/pubspec.yaml
@@ -2,7 +2,7 @@
 version: 0.10.0+1
 author: Dart Team <misc@dartlang.org>
 description: Library to programmatically manipulate source map files.
-homepage: http://www.dartlang.org
+homepage: http://github.com/dart-lang/source_maps
 dependencies:
   path: '>=1.2.0 <2.0.0'
   source_span: '>=1.0.0 <2.0.0'