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>.
apiserver: master count and lease endpoint test
**What this PR does / why we need it**: Adds a test to make sure master count and lease endpoint reconcilers work well together, so we can bump LeaseEndpoint to beta. Based on Jordan's comment https://github.com/kubernetes/kubernetes/pull/58474#issuecomment-369954890.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Issue: #57617
Followup PR: #58474
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
/cc @kubernetes/sig-cluster-lifecycle-api-reviews @kubernetes/sig-cluster-lifecycle-api-reviews
abstract out etcd server creation
test/integration/framework: cleanup master_utils.go
kube-apiserver: move StartTestServer tests into test/integration/master
Fix the failing scale test
kube-apiserver's TestServer now returns a struct instead of individual values