Update etcd election to new API
Update etcd election to new API

Martin2112/trillian,google/trillian,daviddrysdale/trillian,RJPercival/trillian,RJPercival/trillian,AlCutter/trillian,Martin2112/trillian,AlCutter/trillian,gdbelvin/trillian,codingllama/trillian,daviddrysdale/trillian,google/trillian,Martin2112/trillian,gdbelvin/trillian,codingllama/trillian,gdbelvin/trillian,daviddrysdale/trillian