message: impl Display and Error trait for the chain_addr's Error type
diff: @@ -87,6 +87,20 @@ pub enum Error {
  MismatchPrefix,
  }
  +impl std::fmt::Display for Error {
  + fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
  + match self {
  + Error::EmptyAddress => write!(f, "empty address"),
  + Error::InvalidKind => write!(f, "invalid kind"),
  + Error::InvalidAddress => write!(f, "invalid address"),
  + Error::InvalidInternalEncoding => write!(f, "invalid internal encoding"),
  + Error::InvalidPrefix => write!(f, "invalid prefix"),
  + Error::MismatchPrefix => write!(f, "mismatch prefix"),
  + }
  + }
  +}
  +impl std::error::Error for Error {}
  +
  impl From<redeem::Error> for Error {
  fn from(_: redeem::Error) -> Error {
  Error::InvalidAddress
  