Update CHANGELOG about adding custom object status and scale api

Author: roycaihw

CHANGELOG.md

@@ -2,6 +2,9 @@
 **New Features:**
 - Add support for refreshing Azure tokens [kubernetes-client/python-base#77](https://github.com/kubernetes-client/python-base/pull/77)
 
+**New API:**
+- Add custom object status and scale api [kubernetes-client/gen#72](https://github.com/kubernetes-client/gen/pull/72)
+
 # v7.0.0b1
 **New Features:**
 - Add Azure support to authentication loading [kubernetes-client/python-base#74](https://github.com/kubernetes-client/python-base/pull/74)