feature request: integrate chia-exporter

[fisherwei]

https://github.com/Chia-Network/chia-exporter

collect metrics to prometheus

[guydavis]

Please try enabling this in the most recent machinaris:develop image.

[fisherwei]

you rock!

[fisherwei]

suggestion: chia_exporter runs in harvester mode too.

[guydavis]

Good enhancement. I've now added that launch to machinaris:develop image when mode=harvester as well. Will be in the next release.