Missed CHANGELOG file in GitHub import:

2850fc68709a34c741c1706fb207d2e6dab19594

Update travis to run 2.4.0 and dev

PiperOrigin-RevId: 308662083
diff --git a/CHANGELOG.md b/CHANGELOG.md
index cfe10bc..9d485e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
   clients who use the Mock class in unconventional ways, such as overriding
   `noSuchMethod` on a class which extends Mock. To fix, or prepare such code,
   add a second parameter to such overriding `noSuchMethod` declaration.
+* Increase minimum Dart SDK to `2.4.0`.
 
 ## 4.1.1