policies: Replace Joe's graphite graphs with Grafana
policies: Replace Joe's graphite graphs with Grafana

It seems the link doesn't show any results anymore and nowadays we have
Grafana.

Change-Id: Ie8caf2b845c754cb307b61619bfd89e40532078e

mahak/neutron,huntxu/neutron,noironetworks/neutron,huntxu/neutron,mahak/neutron,eayunstack/neutron,noironetworks/neutron,openstack/neutron,mahak/neutron,eayunstack/neutron,openstack/neutron,openstack/neutron