add startup sequence duration and readyz endpoint
add rbac bootstrapping policy for readyz
add integration test around grace period and readyz
rename startup sequence duration flag
copy health checks to fields
rename health-check installed boolean, refactor clock injection logic
cleanup clock injection code
remove todo about poststarthook url registration from healthz
Add a smoke test that checks for the existence of some representative
paths from the apiextensions-server and the kube-aggregator server,
both part of the delegation chain in kube-apiserver.
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
