Updated link to latest torrent version

Author: wrichert

ch05/README.md

@@ -5,7 +5,7 @@ The book chapter is based on StackExchange's data blob from August 2012:
 [http://www.clearbits.net/get/2076-aug-2012.torrent](http://www.clearbits.net/get/2076-aug-2012.torrent)
 
 After publishing the book, StackExchange stayed as awesome as it always has been and released an updated version:
-[http://www.clearbits.net/get/2155-sept-2013.torrent](http://www.clearbits.net/get/2155-sept-2013.torrent)
+[https://archive.org/download/stackexchange/stackexchange_archive.torrent](https://archive.org/download/stackexchange/stackexchange_archive.torrent)
 
 Note that using the latest version, you will get slightly different results.