Hi,
This is not supposed to be tested on live site. If you have a production site; you can test the plugin on that. And always take a backup of your database before proceeding with it.
The link provided is for the master branch of rtMedia 3.0. All the current development is going on that branch. It will not guarantee a full fledged working of the plugin; since we are still in process of giving it a final touch. You can consider it as a pre-beta version. You can fork the branch and get the code. The very same code can be put into your plugins directory of your wordpress site.
Please let us know if you have any further doubts.
Regards.