Implement std::error::Error for totp-rs error types

Signed-off-by: constantoine <cleo.rebert-ext@treezor.com>

src/rfc.rs

@@ -14,6 +14,8 @@ pub enum Rfc6238Error {
     SecretTooSmall(usize),
 }
 
+impl std::error::Error for Rfc6238Error {}
+
 impl std::fmt::Display for Rfc6238Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {

src/url_error.rs

@@ -22,6 +22,8 @@ pub enum TotpUrlError {
     AccountNameDecoding(String),
 }
 
+impl std::error::Error for TotpUrlError {}
+
 impl std::fmt::Display for TotpUrlError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {