message: ensure binding or namespace-id are required in Clap ArgGroup
diff: @@ -57,8 +57,9 @@ fn run() -> Result<(), failure::Error> {
  .long("namespace-id")
  .value_name("ID")
  .takes_value(true);
  - let kv_namespace_specifier_group =
  - ArgGroup::with_name("namespace-specifier").args(&["binding", "namespace-id"]);
  + let kv_namespace_specifier_group = ArgGroup::with_name("namespace-specifier")
  + .args(&["binding", "namespace-id"])
  + .required(true);
  // This arg is for any action that uses environments (e.g. KV subcommands, publish)
  let environment_arg = Arg::with_name("env")
  