update changelog and readme

Author: roycaihw

CHANGELOG.md

@@ -1,6 +1,6 @@
-# v18.0.0-snapshot
+# v18.20.0
 
-Kubernetes API Version: To Be Updated
+Kubernetes API Version: 1.18.20
 
 ### Feature
 - Support for the dryRun parameter has been added to the dynamic client. ([kubernetes-client/python-base#247](https://github.com/kubernetes-client/python-base/pull/247), [@gravesm](https://github.com/gravesm))

README.md

@@ -87,7 +87,7 @@ supported versions of Kubernetes clusters.
 - [client 11.y.z](https://pypi.org/project/kubernetes/11.0.0/): Kubernetes 1.14 or below (+-), Kubernetes 1.15 (✓), Kubernetes 1.16 or above (+-)
 - [client 12.y.z](https://pypi.org/project/kubernetes/12.0.1/): Kubernetes 1.15 or below (+-), Kubernetes 1.16 (✓), Kubernetes 1.17 or above (+-)
 - [client 17.y.z](https://pypi.org/project/kubernetes/17.17.0/): Kubernetes 1.16 or below (+-), Kubernetes 1.17 (✓), Kubernetes 1.18 or above (+-)
-- [client 18.y.z](https://pypi.org/project/kubernetes/18.20.0b1/): Kubernetes 1.17 or below (+-), Kubernetes 1.18 (✓), Kubernetes 1.19 or above (+-)
+- [client 18.y.z](https://pypi.org/project/kubernetes/18.20.0/): Kubernetes 1.17 or below (+-), Kubernetes 1.18 (✓), Kubernetes 1.19 or above (+-)
 
 > See [here](#homogenizing-the-kubernetes-python-client-versions) for an explaination of why there is no v13-v16 release.
 
@@ -121,12 +121,13 @@ between client-python versions.
 | 10.0 Alpha/Beta | Kubernetes main repo, 1.14 branch    | ✗                             |
 | 10.0            | Kubernetes main repo, 1.14 branch    | ✗                             |
 | 11.0 Alpha/Beta | Kubernetes main repo, 1.15 branch    | ✗                             |
-| 11.0            | Kubernetes main repo, 1.15 branch    | ✓                             |
+| 11.0            | Kubernetes main repo, 1.15 branch    | ✗                             |
 | 12.0 Alpha/Beta | Kubernetes main repo, 1.16 branch    | ✗                             |
 | 12.0            | Kubernetes main repo, 1.16 branch    | ✓                             |
 | 17.0 Alpha/Beta | Kubernetes main repo, 1.17 branch    | ✗                             |
 | 17.0            | Kubernetes main repo, 1.17 branch    | ✓                             |
-| 18.0 Alpha/Beta | Kubernetes main repo, 1.18 branch    | ✓                             |
+| 18.0 Alpha/Beta | Kubernetes main repo, 1.18 branch    | ✗                             |
+| 18.0            | Kubernetes main repo, 1.18 branch    | ✓                             |
 
 > See [here](#homogenizing-the-kubernetes-python-client-versions) for an explaination of why there is no v13-v16 release.