Implement track requests and add the track organizer role

About track requests:
Create migration that adds the fields submitter_id, state, and
cfp_active to Tracks
Add validations and the self_organized? method to the Track model
Create a new TracksController outide of the admin namespace
Create the relevant views for index, show, new and edit
Modify the admin views for tracks to include extra info for
self-organized tracks

About track organizers:
Create the role when a self-organized track is created
Define track organizer abilities
Modify the roles views and controller to handle the new role

The route for Roles#edit needs to have higher priority than the nested
routes for track roles, otherwise, the word edit in the url is matched
as a track with short_name edit

app/controllers/admin/tracks_controller.rb

@@ -50,10 +50,19 @@ module Admin
       end
     end
 
+    def toggle_cfp_inclusion
+      @track.cfp_active = !@track.cfp_active
+      if @track.save
+        head :ok
+      else
+        head :unprocessable_entity
+      end
+    end
+
     private
 
     def track_params
-      params.require(:track).permit(:name, :description, :color, :short_name)
+      params.require(:track).permit(:name, :description, :color, :short_name, :cfp_active)
     end
   end
 end