Update APIServer admission controllers. (#447)
Update APIServer admission controllers. (#447)

The recommended set is sepecified here:

https://kubernetes.io/docs/admin/admission-controllers/#is-there-a-recommended-set-of-plug-ins-to-use

Fixes #438.
hongchaodeng/bootkube,kubernetes-incubator/bootkube,ericchiang/bootkube,dghubble/bootkube,ericchiang/bootkube,ericchiang/bootkube,dghubble/bootkube,kubernetes-incubator/bootkube,diegs/bootkube,kubernetes-incubator/bootkube,diegs/bootkube,hongchaodeng/bootkube,diegs/bootkube,hongchaodeng/bootkube,dghubble/bootkube