show instance name when ssh-config command is run

[mkinney]

Resolves #63

$ mech ssh-config
Host centos8b
  User vagrant
  Port 22
  UserKnownHostsFile /dev/null
  StrictHostKeyChecking no
  PasswordAuthentication no
  IdentityFile /Users/mikekinney/.mech/insecure_private_key
  IdentitiesOnly yes
  LogLevel FATAL
  HostName 192.168.2.237

$ mech ls | grep centos8b
            centos8b	  192.168.2.237	                     bento/centos-8	 201912.04.0	/Users/mikekinney/Documents/python/mech/mkinney_mech

[mkinney]

@Kronuz Any interest in merging these PRs?

[ColdHeat]

This looks reasonable to me. I've been away from the codebase for sometime but I'm not clear on how self.instance_name appears to be set? Can you add an empty attribute in the classes to denote where it's actually being stored?

[mkinney]

Going to close this PR as I have a much large PR coming.