Correct HMAC docs.
@@ -13,7 +13,6 @@ pub enum Hmac {
/// HMAC (Hash-based Message Authentication Code) as specified in the
/// [RFC 2104](https://tools.ietf.org/html/rfc2104).
///
-/// All available SHA variants are provided by [ring](https://github.com/briansmith/ring).
/// # Usage examples:
/// ### Generating HMAC:
/// ```
