Update changelog.

CHANGELOG.md

@@ -5,13 +5,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+
+## [0.5.1] - 2021-12-15
+### Added
+- Informative error message in session strategy if session support is not
+available.
+
 ### Changed
 
 - `authenticate()` middleware, rather than `initialize()` middleware, extends
 request with `login()`, `logIn()`, `logout()`, `logOut()`, `isAuthenticated()`,
 and `isUnauthenticated()` functions.
-- Session strategy errors with informative message if session support is not
-available.
 
 ## [0.5.0] - 2021-09-23
 ### Changed
@@ -33,4 +37,5 @@ eliminating a race condition in situations where `initialize()` middleware is
 used multiple times in an application with `userProperty` set to different
 values.
 
-[Unreleased]: https://github.com/jaredhanson/passport/compare/v0.5.0...HEAD
+[Unreleased]: https://github.com/jaredhanson/passport/compare/v0.5.1...HEAD
+[0.5.1]: https://github.com/jaredhanson/passport/compare/v0.5.0...v0.5.1