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/github.com/rcrowley/go-metrics/runtime_gccpufraction.go b/demo_test/vendor/github.com/rcrowley/go-metrics/runtime_gccpufraction.go
new file mode 100644
index 0000000..ca12c05
--- /dev/null
+++ b/demo_test/vendor/github.com/rcrowley/go-metrics/runtime_gccpufraction.go
@@ -0,0 +1,9 @@
+// +build go1.5
+
+package metrics
+
+import "runtime"
+
+func gcCPUFraction(memStats *runtime.MemStats) float64 {
+	return memStats.GCCPUFraction
+}