update copyright year

LICENSE

@@ -1,5 +1,5 @@
-Copyright (c) 2011 Sam Stephenson
-Copyright (c) 2012 Yamashita, Yuu
+Copyright (c) 2013 Yamashita, Yuu
+Copyright (c) 2013 Sam Stephenson
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

README.md

@@ -451,8 +451,8 @@ tracker](https://github.com/yyuu/pyenv/issues).
 
 (The MIT license)
 
-* Copyright (c) 2011 Sam Stephenson
-* Copyright (c) 2012 Yamashita, Yuu
+* Copyright (c) 2013 Yamashita, Yuu
+* Copyright (c) 2013 Sam Stephenson
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the