Update CHANGELOG.md

Asa Schachar · web-flow · commit 8d6e7a7313ee · 2019-05-30T08:56:29.000-07:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,5 @@
 ## 3.1.1
-May 30, 2019
+May 30th, 2019
 
 ### Bug Fixes:
 - fix(is_feature_enabled): Added rollout experiment key map for onboarding datafile. ([#168](https://github.com/optimizely/ruby-sdk/pull/168))
