Fix #2, add rake task for PuSH-unsubscribing from remote users who have no

local followers. Remote users' usernames SHOULD be case-sensitive

lib/tasks/subscriptions.rake

@@ -0,0 +1,13 @@
+namespace :subscriptions do
+
+  desc "For all remote accounts that have no local followers, unsubscribe from PuSH"
+  task clear: :environment do
+    accounts = Account.where('(select count(f.id) from follows as f where f.target_account_id = accounts.id) = 0').where.not(domain: nil)
+
+    accounts.each do |a|
+      a.subscription(api_subscription_url(a.id)).unsubscribe
+      a.update!(verify_token: '', secret: '')
+    end
+  end
+
+end