Block pipeline on prometheus-deploy failures
Block pipeline on prometheus-deploy failures

We initially introduced this job without it blocking the pipeline
because prometheus was an experimental thing. It's now something we rely
on, so we should block the pipeline on the job so that we catch broken
config in staging before it reaches prod.

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