Version 0.2.9 - 2023-11-06:
  * Implement `std::error::Error` for `Error`.

Version 0.2.8 - 2023-07-26:
  * Change links in `Cargo.toml` to `https`.
  * Update to `base64` version `0.21`.

Version 0.2.7 - 2022-05-10
  * Fix compilation with digest 0.10.2 and up.

Version 0.2.6 - 2022-01-30
  * Update to hmac 0.12.
  * Update to sha2 0.10.

Version 0.2.5 - 2021-10-03
  * Update to hmac 0.11.
  * Update to crypto-mac 0.11.

Version 0.2.4 - 2020-10-14
  * Fix link to docs.rs in Cargo.toml.
  * Update dependencies.
  * Deprecate unsafe `decode` in favor of safe `decode_unverified` function.