Fix changelog version to match pubspec

R=floitsch@google.com

Review URL: https://codereview.chromium.org//2463773002 .
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2edb5e6..74710a3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 1.9.2
+## 1.10.1
 
 * `Set.difference` now takes a `Set<Object>` as argument.