CHANGELOG.md in glimmer-2.2.0 vs CHANGELOG.md in glimmer-2.2.1

@@ -1,9 +1,14 @@
 # Change Log
 
 Related Change Logs:
 - [glimmer-dsl-swt/CHANGELOG.md](https://github.com/AndyObtiva/glimmer-dsl-swt/blob/master/CHANGELOG.md)
 
+### 2.2.1
+
+- Have `ObservableHash` call `notify_observers(key)` upon performing all mutation operations (as expected): `delete`, `delete_if`, `filter!`, `select!`, `keep_if`, `reject!`, `merge!`, `replace`, `shift`, `transform_keys!`, `transform_values!`
+- Fix issue with `Glimmer::DataBinding::Observer.proc {|new_value| ...}.observe(array)` resulting in new_value coming across as `nil when the array is updated
+
 ### 2.2.0
 
 - New `Glimmer::DataBinding::ObservableHash` support for observing `hash[key]=value` mutations
 - Ensure observed ObservableHash values are enhanced with ObservableHash if they were of type Hash
 - Ensure observed ObservableModel values are enhanced with ObservableHash if they were of type Hash