Adds CHANGELOG.md entry

CHANGELOG.md

@@ -24,6 +24,8 @@ All notable changes to this project will be documented in this file. Changes not
 ## Fixed
 - An issue in the `HttpRouter` causing issues to handle routes with overlapping in the tail. ([#379](https://github.com/httpswift/swifter/pull/359), [#382](https://github.com/httpswift/swifter/pull/382)) by [@Vkt0r](https://github.com/Vkt0r)
 
+- Fixes build errors by excluding XC(UI)Test files from regular targets [#397](https://github.com/httpswift/swifter/pull/397)) by [@ChristianSteffens](https://github.com/ChristianSteffens)
+
 ## Changed
 - Performance: Batch reads of websocket payloads rather than reading byte-by-byte. ([#387](https://github.com/httpswift/swifter/pull/387)) by [@lynaghk](https://github.com/lynaghk)