Unable to report version

[raxod502]

When attempting to retrieve the currently installed version of the EC2 Instance Connect CLI, I receive an error message:

% mssh --version
Invalid target
usage: 
            mssh [-t instance_id] [-u profile] [-z availability_zone] [-r region] [supported ssh flags] target [command]

            target                => [user@]instance_id | [user@]hostname
            [supported ssh flags] => [-l login_name] [-p port]
        

options:
  -h, --help           show this help message and exit
  -r , --region        AWS region
  -z , --zone          Availability zone
  -u , --profile       AWS Config Profile
  -t , --instance_id   EC2 Instance ID. Required if target is hostname
  -d, --debug          Turn on debug logging

I think it would be an improvement if the current version number were printed instead.