add support for nomad autoscaler

[attachmentgenie]

https://github.com/hashicorp/nomad-autoscaler
https://www.nomadproject.io/docs/autoscaling

[maxadamo]

@attachmentgenie what do you expect from the module in order to support Autoscaler?
Nomad autoscaler requires additional configuration steps.
At same time the default APM plugin provided by Nomad is not recommended for production use, and you need to configure extra tools like as prometheus, datadog (or community plugins for Openstack and so on).

Shall this module provide a configuration to run Prometheus and the autoscaler container? Do we feel that this is in scope?

I don't have an answer.