message: require a target arg in the client transfer subcommand
diff: @@ -173,7 +173,7 @@ impl<'a, 'b> ClientCommand<'a, 'b> for Transfer {
  ArgGroup::with_name("target-args")
  .arg(target_account::ARG_NAME)
  .arg(target_purse::ARG_NAME)
  - .required(false),
  + .required(true),
  );
  let subcommand = creation_common::apply_common_payment_options(subcommand);
  creation_common::apply_common_creation_options(subcommand, true)
  