Update CHANGELOG

Tobin C. Harding · Tobin C. Harding · commit 208c1f30ea3a · 2019-12-12T14:51:50.000+11:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Write all diagnostics and log messages to stderr.
+
 ## [0.5.0] - 2019-12-06
 
 ### Added
