Error with http://mexitek.github.com/phpColors/

exception = HTTPConnectionPool(host='mexitek.github.com', port=80): Max retries exceeded with url: /phpColors/ (Caused by NameResolutionError("HTTPConnection(host='mexitek.github.com', port=80): Failed to resolve 'mexitek.github.com' ([Errno -5] No address associated with hostname)"))