Add Loomio (Forums/Custom)

Loomio is a unique project as it is built around the decision making process and does not fit perfectly into any of our current categories.

I would say that it best fits into either Communication systems/Custom or Communication systems/Social Networks and Forums.

What do you think @nodiscc?

README.md

@@ -283,6 +283,7 @@ _[Extensible Messaging and Presence Protocol](https://en.wikipedia.org/wiki/XMPP
   * [HumHub](https://www.humhub.org/) - A flexible kit for private social networks ([Source Code](https://github.com/humhub/humhub)) `AGPLv3` `PHP`
   * [Isso](http://posativ.org/isso/) - a lightweight commenting server written in Python and JavaScript. It aims to be a drop-in replacement for Disqus ([Source code](https://github.com/posativ/isso)) `MIT` `Python`
   * [Jappix](https://jappix.com/) - Jappix is an open social platform, that let's you easily get or keep in touch with everyone.
+  * [Loomio](https://www.loomio.org/) - Loomio is a collaborative decision-making tool that makes it easy for anyone to participate in decisions which affect them.  ([Source code](https://github.com/loomio/loomio)) `AGPLv3` `Ruby`
   * [Movim](https://movim.eu/) - A brand new social network, full of awesome features in a modern and smart interface
   * [MyBB](http://mybb.com) - Free, extensible forum software package. ([Source Code](https://github.com/mybb/mybb)) `LGPLv3` `PHP` 
   * [Newebe](http://newebe.org/) - a Distributed Social Network ([Source code](https://github.com/gelnior/newebe)) `AGPLv3` `Python`