VOL-3244 - remove competing mode flag

- removed competing core command line argument
- changed references from affinity router to device discovery

Change-Id: I40aa553762ef7a4f1c87932c5a5b2ed3038ced8d
diff --git a/go.mod b/go.mod
index e3c5839..26a75dc 100644
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@
 	github.com/gogo/protobuf v1.3.0
 	github.com/golang/protobuf v1.3.2
 	github.com/google/uuid v1.1.1
-	github.com/opencord/voltha-lib-go/v3 v3.1.16
+	github.com/opencord/voltha-lib-go/v3 v3.1.21
 	github.com/opencord/voltha-protos/v3 v3.3.9
 	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2
 	github.com/stretchr/testify v1.4.0