Add CHANGELOG for #268

Author: Xerkus

CHANGELOG.md

@@ -22,7 +22,9 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Fixed
 
-- Nothing.
+- [#268](https://github.com/zendframework/zend-servicemanager/pull/268) Fixes
+  ReflectionBasedAbstractFactory trying to instantiate classes with private
+  constructors
 
 ## 3.3.2 - 2018-01-29