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/jessevdk/go-flags/arg.go b/demo_test/vendor/github.com/jessevdk/go-flags/arg.go
new file mode 100644
index 0000000..8ec6204
--- /dev/null
+++ b/demo_test/vendor/github.com/jessevdk/go-flags/arg.go
@@ -0,0 +1,27 @@
+package flags
+
+import (
+	"reflect"
+)
+
+// Arg represents a positional argument on the command line.
+type Arg struct {
+	// The name of the positional argument (used in the help)
+	Name string
+
+	// A description of the positional argument (used in the help)
+	Description string
+
+	// The minimal number of required positional arguments
+	Required int
+
+	// The maximum number of required positional arguments
+	RequiredMaximum int
+
+	value reflect.Value
+	tag   multiTag
+}
+
+func (a *Arg) isRemaining() bool {
+	return a.value.Type().Kind() == reflect.Slice
+}