Merge pull request #1521 from saaketp/master

Added one R book

free-programming-books.md

@@ -1642,6 +1642,7 @@ See also [TeX](#tex)
 * [R packages](http://r-pkgs.had.co.nz) - Hadley Wickham
 * [R practicals](http://www.columbia.edu/~cjd11/charles_dimaggio/DIRE/resources/R/practicalsBookNoAns.pdf) (PDF)
 * [R Programming](http://en.wikibooks.org/wiki/R_Programming)
+* [R Programming for Data Science](https://leanpub.com/rprogramming) (Needs valid email)
 * [R Succinctly, Syncfusion](http://www.syncfusion.com/resources/techportal/ebooks/rsuccinctly) (PDF, Kindle) *(Just fill the fields with any values)*
 * [The R Inferno](http://www.burns-stat.com/pages/Tutor/R_inferno.pdf) (PDF) - Patrick Burns
 * [The R Language](http://stat.ethz.ch/R-manual/R-patched/doc/html/)