message: Add auth-token flag. Group auth-token and certs into auth clap::ArgGroup
diff: use nats;
  use quicli::prelude::*;
  -use structopt::StructOpt;
  +use structopt::{clap::ArgGroup, StructOpt};
  /// NATS utility that can perform basic publish, subscribe, request and reply functions.
  #[derive(Debug, StructOpt)]
  +#[structopt(group = ArgGroup::with_name("auth").required(false))]
  struct Cli {
  /// NATS server
  #[structopt(long, short, default_value = "demo.nats.io")]
  server: String,
  /// User Credentials File
  - #[structopt(long = "creds")]
  + #[structopt(long = "creds", group = "auth")]
  creds: Option<String>,
  + /// Server authorization token
  + #[structopt(long = "auth-token", group = "auth")]
  + auth_token: Option<String>,
  /// Command: pub, sub, request, reply
  #[structopt(subcommand)]
  @@ -36,6 +40,8 @@ fn main() -> CliResult {
  let opts = if let Some(creds_path) = args.creds {
  nats::Options::with_credentials(creds_path)
  + } else if let Some(token) = args.auth_token {
  + nats::Options::with_token(&token)
  } else {
  nats::Options::new()
  };
  