Update changelog

Author: Sephster

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 ### Changed
 - Conditionally support the `StrictValidAt()` method in lcobucci/jwt so we can use version 4.1.x or greater of the library (PR #1236)
+- When providing invalid credentials, the library now responds with the error message _The user credentials were incorrect_ (PR #1230)
+- Keys are always stored in memory now and are not written to a file in the /tmp directory (PR #1180)
 
 ## [8.3.1] - released 2021-06-04
 ### Fixed