[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/go.etcd.io/etcd/clientv3/retry.go b/vendor/go.etcd.io/etcd/clientv3/retry.go
index 7e855de..6baa52e 100644
--- a/vendor/go.etcd.io/etcd/clientv3/retry.go
+++ b/vendor/go.etcd.io/etcd/clientv3/retry.go
@@ -17,8 +17,8 @@
 import (
 	"context"
 
-	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
-	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
 
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
@@ -179,10 +179,6 @@
 	return rcc.cc.MemberUpdate(ctx, in, opts...)
 }
 
-func (rcc *retryClusterClient) MemberPromote(ctx context.Context, in *pb.MemberPromoteRequest, opts ...grpc.CallOption) (resp *pb.MemberPromoteResponse, err error) {
-	return rcc.cc.MemberPromote(ctx, in, opts...)
-}
-
 type retryMaintenanceClient struct {
 	mc pb.MaintenanceClient
 }