Merge pull request #23135 from maclover7/add-22950-changelog

Add CHANGELOG.md entry for #22950

actioncable/CHANGELOG.md

+*   Create notion of an `ActionCable::SubscriptionAdapter`.
+    Separate out Redis functionality into `AC::SA::Redis`,
+    and add a PostgreSQL adapter as well. Configuration file
+    for ActionCable was changed from `config/redis/cable.yml`
+    to `config/cable.yml`
+
+   *Jon Moss*
+
 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
 *   Added to Rails!