SEBA-902 single-olt tests;
Pin protoc-gen-go to 1.3.2 to resolve compatibility issue;
Run go mod tidy / go mod vendor on importer;
Add Go Module support to demotest

Change-Id: Ifde824fc9a6317b0adc1e12bea54ee1f9b788906
diff --git a/demo_test/vendor/google.golang.org/protobuf/internal/fieldnum/timestamp_gen.go b/demo_test/vendor/google.golang.org/protobuf/internal/fieldnum/timestamp_gen.go
new file mode 100644
index 0000000..b4346fb
--- /dev/null
+++ b/demo_test/vendor/google.golang.org/protobuf/internal/fieldnum/timestamp_gen.go
@@ -0,0 +1,13 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Code generated by generate-protos. DO NOT EDIT.
+
+package fieldnum
+
+// Field numbers for google.protobuf.Timestamp.
+const (
+	Timestamp_Seconds = 1 // optional int64
+	Timestamp_Nanos   = 2 // optional int32
+)