puppet: Add cronjob to run delete_old_unclaimed_attachments daily.

puppet/zulip/files/cron.d/delete-old-unclaimed-attachments

@@ -0,0 +1,6 @@
+SHELL=/bin/bash
+PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
+USER=zulip
+
+# Daily cronjob for cleaning up old, unclaimed attachments and their corresponding files.
+0 6 * * * zulip /home/zulip/deployments/current/manage.py delete_old_unclaimed_attachments -f >/dev/null

puppet/zulip/manifests/app_frontend_once.pp

@@ -67,6 +67,14 @@ class zulip::app_frontend_once {
     source => 'puppet:///modules/zulip/cron.d/archive-messages',
   }
 
+  file { '/etc/cron.d/delete-old-unclaimed-attachments':
+    ensure => file,
+    owner  => 'root',
+    group  => 'root',
+    mode   => '0644',
+    source => 'puppet:///modules/zulip/cron.d/delete-old-unclaimed-attachments',
+  }
+
   file { '/etc/cron.d/clearsessions':
     ensure => file,
     owner  => 'root',