CHANGELOG.markdown in image_optim_rails-0.4.1 vs CHANGELOG.markdown in image_optim_rails-0.4.2

@@ -1,8 +1,12 @@
 # ChangeLog
 
 ## unreleased
 
+## v0.4.2 (2019-05-25)
+
+* Enable frozen string literals [@toy](https://github.com/toy)
+
 ## v0.4.1 (2017-07-09)
 
 * Relax `image_optim` dependency [#5](https://github.com/toy/image_optim_rails/issues/5) [@toy](https://github.com/toy)
 
 ## v0.4.0 (2017-05-31)