message: [config] Fix libra-config -r default
  "Validator" is not valid.
  Closes:
  Approved by: bmwill
diff: @@ -28,7 +28,7 @@ struct Args {
  #[structopt(short = "m", long)]
  /// File location from which to load faucet account generated via generate_keypair tool
  faucet_account_file: String,
  - #[structopt(short = "r", long, default_value = "Validator")]
  + #[structopt(short = "r", long, default_value = "validator")]
  /// Role for the nodes: one of {"validator", "full_node"}
  role: String,
  #[structopt(short = "u", long)]
  