Release notes for M67 (#5127)

Author: christibbs

FirebaseInAppMessaging/CHANGELOG.md

@@ -1,3 +1,8 @@
+# 2020-03-17 -- v0.19.1
+- [fixed] Fixed display issue with banner messages on iPad Pro 11" (#4714).
+- [fixed] Fixed 400 errors from backend due to a bug in the Instance ID SDK (#3887).
+- [changed] Internal change in in-app message A/B test flow (#5078).
+
 # 2020-03-10 -- v0.19.0
 - [added] Added SDK support for A/B testing in-app messages.