enable version subcmd and --version flag for root cmd and all subcmds

cmd/rules.go

@@ -18,8 +18,9 @@ func init() {
 }
 
 var rulesCmd = &cobra.Command{
-	Use:   "rules",
-	Short: "Rules management utility",
+	Use:     "rules",
+	Version: rootCmd.Version,
+	Short:   "Rules management utility",
 	Long: `On each subcommand you'll have available at least two flags:
 "username" and "id". You must either set only one of them
 or none. If you set one of them, the command will apply to