Set correct date of release 4.2.0

Author: sliverc

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 Note that in line with [Django REST Framework policy](http://www.django-rest-framework.org/topics/release-notes/),
 any parts of the framework not mentioned in the documentation should generally be considered private API, and may be subject to change.
 
-## [4.2.0] - 2021-05-03
+## [4.2.0] - 2021-05-12
 
 ### Added