Fix for crate consumers not finding Signature trait methods (#287)

Author: itowlson

src/invoice/signature.rs

@@ -204,7 +204,7 @@ impl KeyEntry {
             }
             Some(txt) => {
                 let decoded_txt = base64::decode(txt)?;
-                let sig = EdSignature::from_bytes(decoded_txt.as_slice())?;
+                let sig = EdSignature::try_from(decoded_txt.as_slice())?;
                 key.verify_strict(self.label.as_bytes(), &sig)?;
                 Ok(())
             }

src/invoice/verification.rs

@@ -143,7 +143,7 @@ impl VerificationStrategy {
 
         let pubkey =
             PublicKey::from_bytes(&pk).map_err(|_| SignatureError::CorruptKey(sig.key.clone()))?;
-        let ed_sig = EdSignature::from_bytes(sig_block.as_slice())
+        let ed_sig = EdSignature::try_from(sig_block.as_slice())
             .map_err(|_| SignatureError::CorruptSignature(sig.key.clone()))?;
         pubkey
             .verify_strict(cleartext, &ed_sig)