Use datadog nozzle from gds_master
Use datadog nozzle from gds_master

For some reason we were still deploying from upgrade_go branch.
But we have since fast forwarded gds_master to bring in updates from
upstream and also to hide credentials in log outputs, see

https://github.com/alphagov/paas-graphite-nozzle/pull/4
https://github.com/alphagov/paas-graphite-nozzle/pull/3

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf