Merge pull request #487 from MariosPapasofokli/coursera-courses-update

reactive course does not exist anymore and redirects to the scala specialization

Author: SethTisue

documentation/index.md

@@ -64,7 +64,12 @@ There are a few interactive resources for trying out Scala, to get a look and fe
 
  * [Functional Programming Principles in Scala](https://www.coursera.org/course/progfun), free on Coursera. This is a course about functional programming given by Martin Odersky himself. You can access the course material and exercises by
  signing up for the course.
- * [Principles of Reactive Programming](https://www.coursera.org/course/reactive), free on Coursera. This is a course about concurrency and event-based asynchronous programming in Scala. You can access the course material and exercises by signing up for the course.
+ * [Functional Programming in Scala Specialization](https://www.coursera.org/specializations/scala), free on Coursera. The Specialization provides a hands-on introduction to functional programming using Scala. You can access the courses material and exercises by signing up for the specialization. Includes the following courses:
+    * Functional Programming Principles in Scala
+    * Functional Program Design in Scala
+    * Parallel programming
+    * Big Data Analysis with Scala and Spark
+    * Functional Programming in Scala Capstone
  * **Try Scala In Your Browser!**: There are a handful of websites where you can interactively run Scala code in your browser! Have a look at [scala-js-fiddle](http://www.scala-js-fiddle.com/), [Scala Kata](http://www.scalakata.com/), and [Scastie](http://scastie.org/) for more.
  * [Independent Courseware](http://getscala.com), online self-study or instructor-led Scala and Play courses for a fee.