Added cloud computing interactive tutorials (#3419)

* Added cloud computing interactive tutorials

* Updated Cloud links to be class specific

 Updated Cloud links to be class specific & added registration required

* Fixed index link for cloud computing

* Corrected cloud courses for free tutorials

Some of the introductory courses were not free. These have been corrected and proper free training listed.

free-programming-interactive-tutorials-en.md

@@ -6,6 +6,7 @@
 * [C#](#c-sharp)
 * [C++](#c-1)
 * [Clojure](#clojure)
+* [Cloud Computing](#cloud-computing)
 * [CoffeeScript](#coffeescript)
 * [Erlang](#erlang)
 * [Git](#git)
@@ -66,6 +67,15 @@
 * [Try Clojure](http://www.tryclj.com)
 
 
+### Cloud Computing 
+
+* [AWS API Gateway](https://run.qwiklabs.com/focuses/269?catalog_rank=%7B%22rank%22%3A3%2C%22num_filters%22%3A1%2C%22has_search%22%3Atrue%7D&parent=catalog&search_id=3605949) - *registration required*
+* [AWS Identity and Access Management (IAM)](https://run.qwiklabs.com/focuses/7782?catalog_rank=%7B%22rank%22%3A6%2C%22num_filters%22%3A1%2C%22has_search%22%3Atrue%7D&parent=catalog&search_id=3605942) - *registration required*
+* [AWS Lambda](https://run.qwiklabs.com/focuses/6431?catalog_rank=%7B%22rank%22%3A2%2C%22num_filters%22%3A1%2C%22has_search%22%3Atrue%7D&parent=catalog&search_id=3605949) - *registration required*
+* [AWS Simple Storage Service (S3)](https://run.qwiklabs.com/focuses/7860?catalog_rank=%7B%22rank%22%3A3%2C%22num_filters%22%3A0%2C%22has_search%22%3Atrue%7D&parent=catalog&search_id=3597563) - *registration required*
+* [Google Cloud Platform](https://cloud.google.com/training/free-labs/)
+
+
 ### CoffeeScript
 
 * [Coffeescript Style Guide](https://github.com/polarmobile/coffeescript-style-guide/blob/master/README.md)