Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Remove experimental keystone authenticator
**What this PR does / why we need it**:
experimental-keystone-url and experimental-keystone-ca-file were always
experimental. So we don't need a deprecation period.
KeystoneAuthenticator was on the server side and needed userid/password
to be passed in and used that to authenticate with Keystone. We now
have authentication and authorization web hooks that can be used. There
is a external repo with a webook for keystone which works fine along
with the kubectl auth provider that was added in:
a0cebcb559
So we don't need this older style / hard coded / experimental code
anymore.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
kube-apiserver: the experimental in-tree Keystone password authenticator has been removed in favor of extensions that enable use of Keystone tokens.
```
2a8049890a