Icon Request: fa-activitypub

![image](https://user-images.githubusercontent.com/164785/36536420-36dc186a-17cd-11e8-9341-b5b9449c84e6.png)


I request the addition of the [ActivityPub](https://activitypub.rocks/) icon. It is the emerging [W3C standrard protocol](https://www.w3.org/TR/activitypub/) for decentralized social networking.

### possible usecase:
Personal website linking to an ActivityPub powered webservice like Mastodon, GNUSocial, ... , .... .


> As SVG isn't an allowed attachement format [I zipped up the plain logo](https://github.com/ForkAwesome/Fork-Awesome/files/1747711/ActivityPub-logo-symbol_SW.svg.zip).