Added "Computational and Inferential Thinking" (#2201)

* Added "Computational and Inferential Thinking"

* Remove trailing slash

* Reorder alphabetically

free-programming-books.md

@@ -406,6 +406,7 @@
 * [Category Theory for the Sciences](http://category-theory.mitpress.mit.edu)
 * [CK-12 Probability and Statistics - Advanced](http://www.ck12.org/book/Probability-and-Statistics---Advanced-%2528Second-Edition%2529/)
 * [Collaborative Statistics](http://cnx.org/contents/5e0744f9-9e79-4348-9237-ed012213a2d6%4040.9)
+* [Computational and Inferential Thinking. The Foundations of Data Science](https://www.inferentialthinking.com)
 * [Computational Geometry](http://web.mit.edu/hyperbook/Patrikalakis-Maekawa-Cho/)
 * [Concepts & Applications of Inferential Statistics](http://vassarstats.net/textbook/)
 * [Differential Equations](http://tutorial.math.lamar.edu/download.aspx) - Paul Dawkins (PDF, use form to download)