Remove all sleeps from `status_endpoint_test.go`
Remove all sleeps from `server_test.go`
Remove all sleeps from `leader_test.go`
Remove all sleeps from `status_endpoint_test.go
Remove all sleeps from `ui_endpoint_test.go`
Remove all sleeps from `kvs_endpoint_test.go`
Remove all sleeps from `internal_endpoint_test.go`
Fix race condition in `TestLeader_FailedMember`