Update README.md

Updated copyright year

Author: ajmeese7

README.md

@@ -21,7 +21,7 @@ free to fork and modify the code.
 
 MIT License
 
-Copyright (c) 2012-2015 Michael Nielsen
+Copyright (c) 2012-2018 Michael Nielsen
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the