message: add support for staging and testnet in the cardano-cli
diff: @@ -195,7 +195,7 @@ fn blockchain_argument_template_definition<'a, 'b>() -> Arg<'a, 'b> {
  .value_name("TEMPLATE")
  .help("the template for the new blockchain")
  .required(false)
  - .possible_values(&["mainnet", "testnet"])
  + .possible_values(&["mainnet", "staging", "testnet"])
  .default_value("mainnet")
  }
  fn blockchain_argument_template_match<'a>(matches: &ArgMatches<'a>)
  @@ -204,6 +204,7 @@ fn blockchain_argument_template_match<'a>(matches: &ArgMatches<'a>)
  match matches.value_of("BLOCKCHAIN_TEMPLATE") {
  None => blockchain::Config::mainnet(),
  Some("mainnet") => blockchain::Config::mainnet(),
  + Some("staging") => blockchain::Config::staging(),
  Some("testnet") => blockchain::Config::testnet(),
  Some(&_) => {
  // this should not be reachable as clap is handling
  