VOL-1643 Update voltha-lib-go to use voltha-protos v3.0.0

and bump up the version to 3.0.0. voltha-protos is modified to be
compatible with the java language proto compilation. It's a major
change and a major version change has been made.

Change-Id: Ifb93430567ddf96aaa0fbf6e5853aad9e1070f6f
diff --git a/go.mod b/go.mod
index a2453d4..c612178 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,4 @@
-module github.com/opencord/voltha-lib-go/v2
+module github.com/opencord/voltha-lib-go/v3
 
 go 1.12
 
@@ -25,7 +25,7 @@
 	github.com/hashicorp/serf v0.8.4 // indirect
 	github.com/jcmturner/gofork v1.0.0 // indirect
 	github.com/onsi/gomega v1.4.2 // indirect
-	github.com/opencord/voltha-protos/v2 v2.1.0
+	github.com/opencord/voltha-protos/v3 v3.0.0
 	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2
 	github.com/pierrec/lz4 v2.3.0+incompatible // indirect
 	github.com/rcrowley/go-metrics v0.0.0-20190826022208-cac0b30c2563 // indirect