add copyright

LICENSE.txt

@@ -214,9 +214,13 @@ License: http://www.apache.org/licenses/LICENSE-2.0
 
 --------------------------------------------------------------------------------
 
-This project includes software from the twox-hash project (MIT License)
+This project includes software from the twox-hash project
 https://github.com/shepmaster/twox-hash
 
+The MIT License (MIT)
+
+Copyright (c) 2015 Jake Goulding
+
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights