VOL-1596 Add Support for handling multicast groups in OpenOLT Adapter.
VOL-1595 Add Support for handling multicast flows in OpenOLT Adapter.

Depends voltha-protos from the patch below:
https://gerrit.opencord.org/#/c/16690/

Change-Id: I1cc9900bd6400bb31aed11beda674138838a21d2
diff --git a/go.mod b/go.mod
index addbbe9..3bc7487 100644
--- a/go.mod
+++ b/go.mod
@@ -7,8 +7,8 @@
 	github.com/cenkalti/backoff/v3 v3.1.1
 	github.com/gogo/protobuf v1.3.1
 	github.com/golang/protobuf v1.3.2
-	github.com/opencord/voltha-lib-go/v2 v2.2.26
-	github.com/opencord/voltha-protos/v2 v2.1.2
+	github.com/opencord/voltha-lib-go/v3 v3.0.0
+	github.com/opencord/voltha-protos/v3 v3.1.0
 	go.etcd.io/etcd v0.0.0-20190930204107-236ac2a90522
 	google.golang.org/grpc v1.25.1
 )