CLI invalid subcommand returns status code zero

[rabbah]

Reported by @ptitzler.

The error status is properly reported if the first command name is invalid. However, if an invalid subcommand is specified the returned status code is zero instead of non-zero.

$ wsk pa
Error: unknown command "pa" for "wsk"
Did you mean this?
    package
    api
Run 'wsk --help' for usage.
unknown command "pa" for "wsk"
Did you mean this?
    package
    api
$ echo $?
1
$ wsk package xxx
work with packages
Usage:
  wsk package [command]
Available Commands:
  bind        bind parameters to a package
  create      create a new package
  update      update an existing package, or create a package if it does not exist
  get         get package
  delete      delete package
  list        list all packages
  refresh     refresh package bindings
Global Flags:
      --apihost HOST         whisk API HOST
      --apiversion VERSION   whisk API VERSION
  -u, --auth KEY             authorization KEY
      --cert string          client cert
  -d, --debug                debug level output
  -i, --insecure             bypass certificate checking
      --key string           client key
  -v, --verbose              verbose output
Use "wsk package [command] --help" for more information about a command.
$ echo $?
0

[csantanapr]

Issue moved to apache/incubator-openwhisk-cli #130 via ZenHub