Support latest Nomad 1.3.+ job descriptor

[MartinAhrer]

Description

I'm trying the new Nomad service registry and replacing the consul provider by the nomad provider. Deploying with levant deploy produces an error message complaining that the key provider is unknown.

Relevant Nomad job specification file

            service {
                name        = "continuousdelivery-api"
                provider    = "nomad"
                port        = "http"
            }

Output of levant version:

Levant v0.3.1

Output of consul version:

N/A

Output of nomad version:

Nomad v1.3.2

Additional environment details:

Debug log outputs from Levant:

[ERROR] levant/command: error parsing 'job': 1 error occurred:
	* group: 'api', task: 'api', service (0): invalid key: provider

[Fuco1]

Same problem with max_client_disconnect. Can we get a new tag/release? I see the dependency was already bumped to nomad 1.3.1 three months ago.