prober test, kubeflow testing part (#1845)
prober test, kubeflow testing part (#1845)

* prober test, kubeflow testing part

* add metric for prober itself

* handle review feedback; add counter metrics

* add clean up logic for resource target-https-proxies

* add param for recycle instance groups

* add version param as test target

kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow,kubeflow/kubeflow