Update Changelog.md

Changelog.md

@@ -2,9 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
+## [0.50] - 2020-08-14
+- performance improvment for /poller/services
+
 ## [0.49] - 2020-08-13
-- performance improvement /data/interfaces
-- refactored a new method for testability
+- performance improvement for /data/interfaces
+- refactored service category sorting for better testability
 
 ## [0.48] - 2020-07-02
 - recover update gracefully in case of Kombu exceptions