VOL-1643 Update voltha-lib-go to use voltha-protos v3.0.0

and bump up the version to 3.0.0. voltha-protos is modified to be
compatible with the java language proto compilation. It's a major
change and a major version change has been made.

Change-Id: Ifb93430567ddf96aaa0fbf6e5853aad9e1070f6f
diff --git a/pkg/db/kvstore/etcdclient.go b/pkg/db/kvstore/etcdclient.go
index 234bf05..7096748 100644
--- a/pkg/db/kvstore/etcdclient.go
+++ b/pkg/db/kvstore/etcdclient.go
@@ -19,7 +19,7 @@
 	"context"
 	"errors"
 	"fmt"
-	"github.com/opencord/voltha-lib-go/v2/pkg/log"
+	"github.com/opencord/voltha-lib-go/v3/pkg/log"
 	v3Client "go.etcd.io/etcd/clientv3"
 	v3Concurrency "go.etcd.io/etcd/clientv3/concurrency"
 	v3rpcTypes "go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"