cf-remote help output should indicate valid commands

> $ cf-remote -H $(hostname)
cf-remote: Invalid or missing command

> $ cf-remote -h
usage: cf-remote [-h] [--hosts HOSTS] [--clients CLIENTS] [--hub HUB]
                 [--bootstrap BOOTSTRAP] [--package PACKAGE]
                 [--hub-package HUB_PACKAGE] [--client-package CLIENT_PACKAGE]
                 [--log-level LOG_LEVEL] [--demo] [--call-collect]
                 [--version [VERSION]]
                 [command] [args [args ...]]

Spooky CFEngine at a distance

positional arguments:
  command               Action to perform (default: None)
  args                  Arguments (default: None)

optional arguments:
  -h, --help            show this help message and exit
  --hosts HOSTS, -H HOSTS
                        Which hosts to connect to (ssh) (default: None)
  --clients CLIENTS, -c CLIENTS
                        Where to install client package (default: None)
  --hub HUB             Where to install hub package (default: None)
  --bootstrap BOOTSTRAP, -B BOOTSTRAP
                        cf-agent --bootstrap argument (default: None)
  --package PACKAGE     Local path to package for transfer and install
                        (default: None)
  --hub-package HUB_PACKAGE
                        Local path to package for --hub (default: None)
  --client-package CLIENT_PACKAGE
                        Local path to package for --clients (default: None)
  --log-level LOG_LEVEL
                        Specify detail of logging (default: WARNING)
  --demo                Use defaults to make demos smoother (NOT secure)
                        (default: False)
  --call-collect        Enable call collect in --demo def.json (default:
                        False)
  --version [VERSION], -V [VERSION]
                        Print or specify version (default: None)

positional arguments:
  command               Action to perform (info|install|packages|run|sudo|scp) (default: None)
  args                  Arguments (default: None)