Add Dive into Python 3 (Chinese version).

free-programming-books-zh.md

@@ -165,6 +165,7 @@
 ### Python
 * [Django book 2.0](http://djangobook.py3k.cn/2.0/)
 * [深入 Python](http://woodpecker.org.cn/diveintopython/)
+* [深入 Python 3](http://woodpecker.org.cn/diveintopython3/)
 * [笨办法学 Python](http://sebug.net/paper/books/LearnPythonTheHardWay/)
 * [简明 Python 教程](http://woodpecker.org.cn/abyteofpython_cn/chinese/) (《A Byte of Python》中文版)