Flaky test: hyperkit osx restart (TestStartStop)

[medyagh]

As seen in osx hyperkit integration test : https://storage.googleapis.com/minikube-builds/logs/4380/OSX-Hyperkit.txt

    --- FAIL: TestStartStop/nocache_oldest (170.23s)
        start_stop_delete_test.go:105: current-context is not set to minikube
        util.go:130: Error running command: start --vm-driver=hyperkit  --v=10 --logtostderr --bootstrapper=kubeadm --cache-images=false --kubernetes-version=v1.10.13 --kvm-network=default --alsologtostderr --v=2 . Output: * minikube v1.1.1 on darwin (amd64)
            * Tip: Use 'minikube start -p <name>' to create a new cluster, or 'minikube delete' to delete this one.
            * Restarting existing hyperkit VM for "minikube" ...

More logs from that build:

 03:58:11 | ! I0615 03:58:11.480450   21974 cluster.go:95] Skipping create...Using existing machine configuration
 03:58:11 | > * Tip: Use 'minikube start -p <name>' to create a new cluster, or 'minikube delete' to delete this one.
 03:58:11 | ! I0615 03:58:11.508281   21974 cluster.go:114] Machine state:  Stopped
 03:58:11 | > * Restarting existing hyperkit VM for "minikube" ...
 03:58:11 | ! E0615 03:58:11.541881   21974 start.go:547] StartHost: start: unexpected EOF
 03:58:11 | ! I0615 03:58:11.541926   21974 utils.go:123] non-retriable error: start: unexpected EOF
 03:58:11 | ! W0615 03:58:11.541997   21974 exit.go:100] Unable to start VM: start: unexpected EOF
 03:58:11 | ! X Unable to start VM: start: unexpected EOF
 03:58:11 | ! * Sorry that minikube crashed. If this was unexpected, we would love to hear from you:
 03:58:11 | !   - https://github.com/kubernetes/minikube/issues/new

[medyagh]

closing this in favor of #4501, it seems to be the same source of problem.