Adding command checks for 'account' and 'cluster' commands

[ghost]

before:

$ uhc account notacommand
$ 

after:

$ uhc account notacommand
INVALID COMMAND
Usage:
  uhc account COMMAND [flags]
  uhc account [command]

Available Commands:
  orgs        List organizations.
  quota       Retrieve cluster quota information.
  roles       Retrieve information of the different roles
  status      Status of current user.
  users       Retrieve users and their roles

Flags:
  -h, --help   help for account

Global Flags:
      --alsologtostderr                  log to standard error as well as files
      --debug                            Enable debug mode.
      --log_backtrace_at traceLocation   when logging hits line file:N, emit a stack trace (default :0)
      --log_dir string                   If non-empty, write log files in this directory
      --logtostderr                      log to standard error instead of files (default true)
      --stderrthreshold severity         logs at or above this threshold go to stderr (default 2)
  -v, --v Level                          log level for V logs
      --vmodule moduleSpec               comma-separated list of pattern=N settings for file-filtered logging

Use "uhc account [command] --help" for more information about a command.

[app-sre-bot]

Can one of the admins verify this patch?