puppet: Move /tmp to local storage on Postgres master servers

(imported from commit eae0a31faad6d95c8e2b55c11481aa19d7e108f2)

servers/puppet/modules/humbug/files/postgresql/setup_disks.sh

@@ -15,4 +15,9 @@ mount /srv
 pg_ctlcluster 9.1 main stop
 mv /var/lib/postgresql /srv
 ln -s /srv/postgresql/ /var/lib
+
+mv /tmp /srv
+mkdir /tmp
+mount --bind /srv/tmp /tmp
+echo "/srv/tmp   /tmp  bind   defaults,bind 0 0" >> /etc/fstab
 pg_ctlcluster 9.1 main start