Upgraded grpc lib version

go.mod

@@ -11,7 +11,7 @@ require (
         github.com/peterbourgon/diskv v2.0.1+incompatible // indirect
         github.com/xanzy/go-gitlab v0.37.0
         golang.org/x/net v0.0.0-20200707034311-ab3426394381
-        google.golang.org/grpc v1.27.0
+        google.golang.org/grpc v1.31.0
         google.golang.org/protobuf v1.24.0
         gopkg.in/inf.v0 v0.9.1 // indirect
         gopkg.in/yaml.v2 v2.3.0