VOL-2172: Delete tech-profile on ONU
- Changes to supporting DELETE_TCONT_REQ and DELETE_GEM_PORT_REQ
- Bug fix to not delete tp instance for ONU-SingleInstance case
- Use voltha proto version 2.1.1
- Use voltha-lib-go version 2.2.19
- Bump voltha-openolt-adapter version to 2.2.4

Change-Id: I8caa4d13fec37227befddbe2444489b923169fbe
diff --git a/go.mod b/go.mod
index 06cdf31..08c6f75 100644
--- a/go.mod
+++ b/go.mod
@@ -5,9 +5,8 @@
 require (
 	github.com/gogo/protobuf v1.3.1
 	github.com/golang/protobuf v1.3.2
-	github.com/opencord/voltha-lib-go/v2 v2.2.18
-	github.com/opencord/voltha-protos/v2 v2.1.0
-	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2 // indirect
+	github.com/opencord/voltha-lib-go/v2 v2.2.19
+	github.com/opencord/voltha-protos/v2 v2.1.1
 	go.etcd.io/etcd v0.0.0-20190930204107-236ac2a90522
 	google.golang.org/grpc v1.25.1
 )