fix youtube length and link

Author: philipmjohnson

README.md

@@ -167,9 +167,9 @@ If you see ways to solve these problems, please feel free to fork this code and
 Screencast
 ----------
 
-Click the image below to watch a 13 minute walkthrough of this example:
+Click the image below to watch a 28 minute walkthrough of this example:
 
-[<img src="https://raw.github.com/ics-software-engineering/play-example-form/master/doc/play-example-form-screencast.png" width="400">](https://www.youtube.com/watch?v=247H9NVpMME)
+[<img src="https://raw.github.com/ics-software-engineering/play-example-form/master/doc/play-example-form-screencast.png" width="400">](http://www.youtube.com/watch?v=247H9NVpMME)
 
 
 Acknowledgements