fix history

Author: FumingZhang

src/aks-preview/HISTORY.rst

@@ -12,15 +12,14 @@ To release a new version, please select a new version number (usually plus 1 to
 Pending
 +++++++
 
-18.0.0b19
+18.0.0b20
 +++++++
 * Add command `az aks bastion` to enable connections to managed Kubernetes clusters via Azure Bastion.
-* Add support for `ManagedSystem` Agent Pool Mode.
 
 18.0.0b19
 +++++++
-- Add `--localdns-config` to `az aks nodepool add` and to `az aks nodepool update` to support configuring a local DNS profile for agent pools.
-
+* Add support for `ManagedSystem` Agent Pool Mode.
+* Add `--localdns-config` to `az aks nodepool add` and to `az aks nodepool update` to support configuring a local DNS profile for agent pools.
 
 18.0.0b18
 +++++++

src/aks-preview/setup.py

@@ -9,7 +9,7 @@
 
 from setuptools import setup, find_packages
 
-VERSION = "18.0.0b19"
+VERSION = "18.0.0b20"
 
 CLASSIFIERS = [
     "Development Status :: 4 - Beta",