def fetch_machines(host)
      Fleetctl.logger.info 'Fetching machines from host: '+host.inspect
      clear
      Fleetctl::Command.new('list-machines', '-l') do |runner|
        runner.run(host: host)
        new_machines = parse_machines(runner.output)
        if runner.exit_code == 0
          return true
        else
          return false
        end
      end
    end
def fetch_machines(host)
      Fleetctl.logger.info 'Fetching machines from host: '+host.inspect
      clear
      Fleetctl::Command.new('list-machines', '-l') do |runner|
        runner.run(host: host)
        new_machines = parse_machines(runner.output)
        if runner.exit_code == 0
          return true
        else
          return false
        end
      end
    end
attempts a list-machines action on the given host.
 returns true if successful, else false