Show all valid commands when running ogcli --help

Commands are retrieved using dir() so future commands will show
accordingly.

"ogcli --help" now will print:

usage: ogcli [-h] {create,list,rest,restore,send,set,setup}

positional arguments:
  {create,list,rest,restore,send,set,setup}
                        Subcommand to run

optional arguments:
  -h, --help            show this help message and exit

1 files changed, 3 insertions, 1 deletions

diff --git a/ogcli b/ogcli
index fd6eade..abea632 100755
--- a/ogcli
+++ b/ogcli
@@ -34,7 +34,9 @@ class CLI():
 		self.ogcli = OgCLI(self.cfg)
 
 		parser = argparse.ArgumentParser(prog='ogcli')
-		parser.add_argument('command', help='Subcommand to run')
+		parser.add_argument('command', help='Subcommand to run',
+					choices=[attr for attr in dir(self.ogcli)
+						if not str.startswith(attr, "_")])
 		args = parser.parse_args(sys.argv[1:2])
 
 		if not hasattr(self.ogcli, args.command):