Fix typo

Author: marcospassos

CHANGELOG.md

@@ -18,7 +18,7 @@ There are currently no unreleased changes.
 ### Changed
 
 - Fix reference counting logic.
-- Sets pointer in sub writes to keep parent's writer counting.
+- Set pointer in sub writes to keep parent's writer count.
 
 ## [0.4.0](https://github.com/marcospassos/java-php-serializer/releases/tag/0.4.0) (2017-07-09)
 
@@ -47,4 +47,4 @@ There are currently no unreleased changes.
 
 ## [0.1.0](https://github.com/marcospassos/java-php-serializer/releases/tag/0.1.0) (2017-06-29)
 
-- First beta release
+- First beta release