Update CHANGELOG for Firestore v1.6.0 (#3976)

wilhuff · web-flow · commit 3d91a0fb0d57 · 2019-10-02T11:54:43.000-07:00
diff --git a/Firestore/CHANGELOG.md b/Firestore/CHANGELOG.md
@@ -1,4 +1,6 @@
 # Unreleased
+
+# v1.6.0
 - [feature] Added an `addSnapshotsInSyncListener()` method to
   `FIRFirestore` that notifies you when all your snapshot listeners are
   in sync with each other.
