Merge pull request #685 from krzysztofr/master

Two "Non-Programmers" tutorials for python 2.6&3 added

free-programming-books.md

@@ -1316,6 +1316,8 @@ See also [TeX](#tex)
 * [Making Games with Python & Pygame](http://inventwithpython.com/pygame/chapters/) - Al Sweigart
 * [Modeling Creativity: Case Studies in Python](http://www.clips.ua.ac.be/sites/default/files/modeling-creativity.pdf) - Tom D. De Smedt
 * [Natural Language Processing with Python](http://www.nltk.org/book)
+* [Non-Programmer's Tutorial for Python 2.6](http://en.wikibooks.org/wiki/Non-Programmer%27s_Tutorial_for_Python_2.6)
+* [Non-Programmer's Tutorial for Python 3](http://en.wikibooks.org/wiki/Non-Programmer%27s_Tutorial_for_Python_3)
 * [Porting to Python 3: An In-Depth Guide](http://python3porting.com/)
 * [Problem Solving with Algorithms and Data Structures](http://interactivepython.org/courselib/static/pythonds/index.html)
 * [Program Arcade Games With Python And Pygame](http://programarcadegames.com/)