Add rake task to sync repositories

lib/tasks/tasks.rake

@@ -14,4 +14,9 @@ namespace :tasks do
   task sync_subjects: :environment do
     Notification.subjectable.find_each{|n| n.send(:update_subject, true); print '.' }
   end
+
+  desc "Sync repositories"
+  task sync_repos: :environment do
+    Notification.find_each{|n| n.send(:update_repository); print '.' }
+  end
 end