[VOL-4020]  voltha-lib-go changes for ONU SW upgrade, new Download, Activate,Retrieve APIs

Change-Id: Iaa87a1b74b5f2e25cb0ab43e47f1549683246951
diff --git a/go.sum b/go.sum
index 95e78b7..acbe659 100644
--- a/go.sum
+++ b/go.sum
@@ -136,8 +136,8 @@
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/gomega v1.4.2 h1:3mYCb7aPxS/RU7TI1y4rkEn1oKmPRjNJLNEXgw7MH2I=
 github.com/onsi/gomega v1.4.2/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
-github.com/opencord/voltha-protos/v4 v4.0.12 h1:x8drb8inaUByjVLFbXSiQwRTU//dfde0MKIHyKb1JMw=
-github.com/opencord/voltha-protos/v4 v4.0.12/go.mod h1:W/OIFIyvFh/C0vchRUuarIsMylEhzCRM9pNxLvkPtKc=
+github.com/opencord/voltha-protos/v4 v4.1.1 h1:yovQHC+JQSrw5zxj0UeQqmyFUBQ+487JdG5w5ttrRyc=
+github.com/opencord/voltha-protos/v4 v4.1.1/go.mod h1:W/OIFIyvFh/C0vchRUuarIsMylEhzCRM9pNxLvkPtKc=
 github.com/opentracing/opentracing-go v1.1.0 h1:pWlfV3Bxv7k65HYwkikxat0+s3pV4bsqf19k25Ur8rU=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2 h1:JhzVVoYvbOACxoUmOs6V/G4D5nPVUW73rKvXxP4XUJc=