Mention that Version implements VersionConstraint in the changelog.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1123313003
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32538cc..06f7caa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@
 * Add a `VersionConstraint.allowsAny()` method, which returns whether one
   constraint overlaps another.
 
+* `Version` now implements `VersionRange`.
+
 # 1.1.0
 
 * Add support for the `^` operator for compatible versions according to pub's