Support pulling source job metrics to feed to auto scaler
See #82 . Job master can now optionally subscribe to workers from source jobs to pull metrics. This is gated by a job property. Drop metrics from source jobs are feed to the auto scaler.
See #82 . Job master can now optionally subscribe to workers from source jobs to pull metrics. This is gated by a job property. Drop metrics from source jobs are feed to the auto scaler.