Update free-courses-en.md (#3738)

* Update free-courses-en.md

Updated tutorials for Java, R, SQL

* Update free-courses-en.md

free-courses-en.md

@@ -227,6 +227,7 @@
 * [Introduction to Java](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-092-introduction-to-programming-in-java-january-iap-2010/)
 * [Java for Complete Beginners](http://courses.caveofprogramming.com/courses/java-for-complete-beginners)
 * [Java for Mobile Devices - Introducing Codename One](https://codenameone.teachable.com/p/java-for-mobile-devices-introducing-codename-one)
+* [Java Online Training | Edureka](https://www.youtube.com/watch?v=hBh_CC5y8-s) - (Edureka)
 * [Learn how to program: Java](https://www.learnhowtoprogram.com/java-june-2017) - Epicodus Inc.
 * [Object-Oriented programming with Java, part I](https://moocfi.github.io/courses/2013/programming-part-1/)
 * [Object-Oriented programming with Java, part II](https://moocfi.github.io/courses/2013/programming-part-2/)
@@ -397,6 +398,8 @@
 ### R
 
 * [R Programming](https://www.coursera.org/course/rprog)
+* [R Programming Tutorial](https://www.youtube.com/watch?v=_V8eKsto3Ug) - (Barton Poulson) - (freeCodeCamp)
+* [R Tutorial For Beginners | Edureka](https://www.youtube.com/watch?v=fDRa82lxzaU) - (Edureka)
 
 
 ### RethinkDB
@@ -427,6 +430,7 @@
 ### SQL
 
 * [SQL Tutorial](https://www.youtube.com/playlist?list=PL_RGaFnxSHWr_6xTfF2FrIw-NAOo3iWMy)
+* [SQL Tutorial - Full Database Course for Beginners](https://www.youtube.com/watch?v=HXV3zeQKqGY) - (Mike Dane) - (freeCodeCamp)
 
 
 ### Swift