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/adaptercore/openolt_eventmgr_test.go b/adaptercore/openolt_eventmgr_test.go
index 7430be4..7dbda43 100644
--- a/adaptercore/openolt_eventmgr_test.go
+++ b/adaptercore/openolt_eventmgr_test.go
@@ -23,7 +23,7 @@
 	"time"
 
 	"github.com/opencord/voltha-openolt-adapter/mocks"
-	oop "github.com/opencord/voltha-protos/v2/go/openolt"
+	oop "github.com/opencord/voltha-protos/v3/go/openolt"
 )
 
 func mockEventMgr() *OpenOltEventMgr {