message: feat(error): implement std error for EncryptError
  This makes EncryptError slightly easier to use with anyhow and
  other libraries that leverage `std::error::Error`.
diff: @@ -27,6 +27,14 @@ impl fmt::Display for EncryptError {
  }
  }
  +impl std::error::Error for EncryptError {
  + fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
  + match self {
  + EncryptError::Io(inner) => Some(inner),
  + }
  + }
  +}
  +
  /// The various errors that can be returned during the decryption process.
  #[derive(Debug)]
  pub enum DecryptError {
  