Update CHANGELOG.md

MaxDesiatov · MaxDesiatov · commit 254741be0707 · 2020-10-04T16:40:15.000+01:00
diff --git a/Changelog.md b/Changelog.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Added an end-to-end test for validity of generated `all.css` file.
+  #199 by @MaxDesiatov.
+
 ## [1.0.0-beta.5] - 2020-09-29
 
 ### Added
