Update link to a free version (#3027)

free-programming-books.md

@@ -2120,7 +2120,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [SICP in Python](http://www-inst.eecs.berkeley.edu/~cs61a/sp12/book/) (3.2)
 * [Snake Wrangling For Kids](http://www.briggs.net.nz/snake-wrangling-for-kids.html) (3.x)
 * [Suporting Python 3: An In-Depth Guide](http://python3porting.com) (2.6 - 2.x & 3.1 - 3.x)
-* [Test-Driven Web Development with Python](http://chimera.labs.oreilly.com/books/1234000000754/index.html) (3.3 - 3.x)
+* [Test-Driven Web Development with Python](http://www.obeythetestinggoat.com/pages/book.html#toc) (3.3 - 3.x)
 * [Text Processing in Python](http://gnosis.cx/TPiP/) - David Mertz (2.3 - 2.x)
 * [The Coder's Apprentice: Learning Programming with Python 3](http://www.spronck.net/pythonbook/) - Pieter Spronck (PDF) (3.x)
 * [The Definitive Guide to Jython, Python for the Java Platform](http://www.jython.org/jythonbook/en/1.0) - Josh Juneau, Jim Baker, Victor Ng, Leo Soto, Frank Wierzbicki (2.5)