docs: adds CHANGELOG entry for #259

Author: weierophinney

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 1.2.4 - TBD
+## 1.2.4 - 2019-12-26
 
 ### Added
 
@@ -22,7 +22,7 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Fixed
 
-- Nothing.
+- [#259](https://github.com/zendframework/zend-developer-tools/pull/259) adjusts the casing used when retrieving the "config" service within the `ConfigCollector` to be all lowercase, ensuring it works with all versions of zend-mvc.
 
 ## 1.2.3 - 2019-03-28