Every campaign has an end.

Drop ahoy, because it's more trouble than it's worth. This means dropping
visits, campaigns, targets.

Campaigns are better run to analytics, such as:
* https://matomo.org/docs/tracking-campaigns/
* https://matomo.org/docs/tracking-goals-web-analytics/
* https://support.google.com/analytics/answer/1012040?hl=en

app/controllers/conference_registrations_controller.rb

@@ -52,9 +52,6 @@ class ConferenceRegistrationsController < ApplicationController
     authorize! :create, @registration
 
     if @registration.save
-      # Trigger ahoy event
-      ahoy.track 'Registered', title: 'New registration'
-
       # Sign in the new user
       unless current_user
         sign_in(@registration.user)