Add portmap CNI plugin for k8s >= 1.9
Add portmap CNI plugin for k8s >= 1.9

Older CNI versions don't have the portmap plugin, but we should make
it available.

kubernetes/kops,kubernetes/kops,robinpercy/kops,robinpercy/kops,gambol99/kops,justinsb/kops,aledbf/kops,blakebarnett/kops,blakebarnett/kops,gambol99/kops,aledbf/kops,aledbf/kops,robinpercy/kops,gambol99/kops,blakebarnett/kops,gambol99/kops,blakebarnett/kops,justinsb/kops,kubernetes/kops,aledbf/kops,robinpercy/kops,justinsb/kops