VOL-3248 Support for SetExtValue API

         This commits adds a new SetExtValue API in the VOLTHA
         core and also the handling of the request.

Change-Id: I45b76e4bcc3234842c8404514f5220573ac33211
diff --git a/go.mod b/go.mod
index a10cc84..8618262 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@
 	github.com/golang/protobuf v1.3.2
 	github.com/google/uuid v1.1.1
 	github.com/opencord/voltha-lib-go/v3 v3.2.10
-	github.com/opencord/voltha-protos/v3 v3.4.1
+	github.com/opencord/voltha-protos/v3 v3.4.2
 	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2
 	github.com/stretchr/testify v1.4.0
 	google.golang.org/grpc v1.24.0