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.sum b/go.sum
index 475fa00..3ddfadb 100644
--- a/go.sum
+++ b/go.sum
@@ -200,8 +200,9 @@
 github.com/onsi/gomega v1.4.2/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/opencord/voltha-lib-go/v3 v3.2.10 h1:nPOYyR+WsnL0YawstDUExDF3taKtAEqBu1VuPCvwScE=
 github.com/opencord/voltha-lib-go/v3 v3.2.10/go.mod h1:MIWsmMGxIRLK8dG+CNVcE/cJCzOondyRbwJ1708BYgU=
-github.com/opencord/voltha-protos/v3 v3.4.1 h1:Nrr0jKy7WiMiFlXYiK8z73RvI4K4L5b/top7d3htQQI=
 github.com/opencord/voltha-protos/v3 v3.4.1/go.mod h1:nl1ETp5Iw3avxOaKD8BJlYY5wYI4KeV95aT1pL63nto=
+github.com/opencord/voltha-protos/v3 v3.4.2 h1:ufdFWJz9Gqp+eBJoCPA6LzKpf5lMfhCmf8BLE7dw7kU=
+github.com/opencord/voltha-protos/v3 v3.4.2/go.mod h1:nl1ETp5Iw3avxOaKD8BJlYY5wYI4KeV95aT1pL63nto=
 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/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
@@ -345,7 +346,6 @@
 google.golang.org/grpc v1.23.1/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 google.golang.org/grpc v1.24.0 h1:vb/1TCsVn3DcJlQ0Gs1yB1pKI6Do2/QNwxdKqmc/b0s=
 google.golang.org/grpc v1.24.0/go.mod h1:XDChyiUovWa60DnaeDeZmSW86xtLtjtZbwvSiRnRtcA=
-gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=