[FEATURE] Add support for Nomad service discovery

[protochron]

Is your feature request related to a problem? Please describe.
Right now Netreap depends on both Consul and Nomad. Nomad has the ability to register services directly in the cluster, which removes the need to depend on Consul.

Describe the solution you'd like
We should have a flag to enable Nomad service discovery support, so that we can run Netreap in a mode where it only depends on Nomad and that's it.

Describe alternatives you've considered

Additional context