Updated tools version to 2.0.0

VOL-2647

Change-Id: Ia9510e2677ec78874b66c77a692e4c254513c3ef
diff --git a/go.mod b/go.mod
index 6b80041..3a21901 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/opencord/voltha-protos/v3
 
-go 1.12
+go 1.13
 
 require (
 	github.com/golang/protobuf v1.3.2