go.mod updated with latest voltha-lib-go version before release 2.12

Change-Id: I099d1c5e7511886a1e5e95c8d781dae830b59f4b
diff --git a/go.mod b/go.mod
index 2880a1c..66fd3ad 100644
--- a/go.mod
+++ b/go.mod
@@ -17,7 +17,7 @@
 	github.com/golang/mock v1.6.0
 	github.com/golang/protobuf v1.5.2
 	github.com/google/uuid v1.3.0
-	github.com/opencord/voltha-lib-go/v7 v7.3.2
+	github.com/opencord/voltha-lib-go/v7 v7.4.2
 	github.com/opencord/voltha-protos/v5 v5.4.6
 	github.com/opentracing/opentracing-go v1.2.0
 	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2