Update pmbp.txt

Author: wakaba

doc/pmbp.txt

@@ -134,9 +134,11 @@ possible to enable branched development process.
 
 Wakaba <wakaba@suikawiki.org>.
 
+Thanks to suzak and nanto.
+
 * License
 
-Copyright 2012 Wakaba <wakaba@suikawiki.org>.
+Copyright 2012-2015 Wakaba <wakaba@suikawiki.org>.
 
 This library is free software; you can redistribute it and/or modify
 it under the same terms as Perl itself.