Add missing error check (close #551)
Add missing error check (close #551)

GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold,GoogleContainerTools/skaffold