Add Activity Feed Feature

* Tests incomplete. Need to work on feature tests.
* When a user creates a match request, it shows on activity feed.
* Declined match request shows on activity feed
* Creates activities for creating a match request
* Creates activities for declining a match request
* Create activities for accepting a match
* Add activities for submitting a winner for match
* Add styles to activity feed
Merge pull request #35 from elijahkim/ek/activity-feed

Ek/activity feed