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/sirupsen/logrus/terminal_check_notappengine.go b/demo_test/vendor/github.com/sirupsen/logrus/terminal_check_notappengine.go
new file mode 100644
index 0000000..3293fb3
--- /dev/null
+++ b/demo_test/vendor/github.com/sirupsen/logrus/terminal_check_notappengine.go
@@ -0,0 +1,17 @@
+// +build !appengine,!js,!windows,!nacl,!plan9
+
+package logrus
+
+import (
+	"io"
+	"os"
+)
+
+func checkIfTerminal(w io.Writer) bool {
+	switch v := w.(type) {
+	case *os.File:
+		return isTerminal(int(v.Fd()))
+	default:
+		return false
+	}
+}