Refactor external snapshotter to use csi-lib-utils/rpc#97

Merged

k8s-ci-robot merged 2 commits intokubernetes-csi:masterfrom andrewsykim:consistent-sidecar

Apr 1, 2019

+16,515-5,528

Commits on Mar 30, 2019

update csi-lib-utils to v0.4.0
andrewsykim
committed

Commits on Apr 1, 2019

refactor external snapshotter to use csi-lib-utils/rpc
andrewsykim
committed