Update to free books (EbookFoundation#2671)

* Update free-courses-en.md

Added a Python online resource under the Python course section.

* Update free-programming-books.md

Added techbeamers to meta-list section.

Author: techbeamers

Diff for: free-programming-books.md

@@ -225,6 +225,7 @@
 * [Papers we love](https://github.com/papers-we-love/papers-we-love)
 * [Red Gate Books](http://www.red-gate.com/community/books/index)
 * [Stef's Free Online Smalltalk Books](http://stephane.ducasse.free.fr/FreeBooks/)
+* [TechBeamers.com](http://www.techbeamers.com)
 * [TechBooksForFree.com](http://www.techbooksforfree.com)
 * [The Definitive C++ Book Guide and List](http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list)
 * [Theassayer.org](http://theassayer.org)

Diff for: free-programming-interactive-tutorials-en.md

@@ -174,6 +174,7 @@
 * [Codecademy Python course](https://www.codecademy.com/learn/python)
 * [How to Think Like a Computer Scientist: Learning with Python, Interactive Edition](http://interactivepython.org/courselib/static/thinkcspy/index.html)
 * [Learn Python](http://www.learnpython.org)
+* [Learn Python Step by Step](http://www.techbeamers.com/python-tutorial-step-by-step)
 * [Python Koans](https://github.com/gregmalcolm/python_koans)
 
 
@@ -197,6 +198,11 @@
 * [Scala Exercises](https://www.scala-exercises.org) 
 
 
+### Selenium
+
+* [Selenium Tutorial - Web Automation](http://www.techbeamers.com/selenium-webdriver-tutorial)
+
+
 ### SQL
 
 * [SQL at Codecademy](https://www.codecademy.com/courses/learn-sql)