Remove references to etcd2 in v1.13 since support has been removed#11414

Merged

k8s-ci-robot merged 3 commits intokubernetes:dev-1.13from spiffxp:rm-etcd2-refs

Nov 30, 2018

+26-454

Commits on Nov 29, 2018

Commits on Nov 30, 2018

Address review comments
spiffxp
committed