Bump Consul, Vault, and Nomad version defaults
Bumped Consul to version 1.2.0, Vault to version 0.8.3, and Nomad to version 0.8.4 for default HashiStack AMI query.
Bumped Consul to version 1.2.0, Vault to version 0.8.3, and Nomad to version 0.8.4 for default HashiStack AMI query.