etcd: Etcd client with dialer passthrough.

Allows user to contact etcd with arbitrary connection types, useful
when proxying through the Kubernetes API server.

Protobuf types are wrapped such that downstream consumers do not
need to import etcd packages.

Signed-off-by: Naadir Jeewa <jeewan@vmware.com>

go.mod

@@ -22,13 +22,14 @@ require (
 	github.com/prometheus/procfs v0.0.5 // indirect
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/viper v1.3.2
+	go.etcd.io/etcd v0.0.0-20191023171146-3cf2f69b5738
 	go.uber.org/atomic v1.4.0 // indirect
-	go.uber.org/zap v1.10.0 // indirect
 	golang.org/x/crypto v0.0.0-20190923035154-9ee001bba392 // indirect
 	golang.org/x/net v0.0.0-20191004110552-13f9640d40b9
 	golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45
 	golang.org/x/sys v0.0.0-20191008105621-543471e840be // indirect
 	golang.org/x/time v0.0.0-20191024005414-555d28b269f0 // indirect
+	google.golang.org/grpc v1.23.1
 	k8s.io/api v0.0.0-20191121015604-11707872ac1c
 	k8s.io/apiextensions-apiserver v0.0.0-20190918161926-8f644eb6e783
 	k8s.io/apimachinery v0.0.0-20191121015412-41065c7a8c2a