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/golang.org/x/sys/unix/syscall_unix_gc_ppc64x.go b/demo_test/vendor/golang.org/x/sys/unix/syscall_unix_gc_ppc64x.go
new file mode 100644
index 0000000..86dc765
--- /dev/null
+++ b/demo_test/vendor/golang.org/x/sys/unix/syscall_unix_gc_ppc64x.go
@@ -0,0 +1,24 @@
+// Copyright 2018 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.
+
+// +build linux
+// +build ppc64le ppc64
+// +build !gccgo
+
+package unix
+
+import "syscall"
+
+func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.Errno) {
+	return syscall.Syscall(trap, a1, a2, a3)
+}
+func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno) {
+	return syscall.Syscall6(trap, a1, a2, a3, a4, a5, a6)
+}
+func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.Errno) {
+	return syscall.RawSyscall(trap, a1, a2, a3)
+}
+func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno) {
+	return syscall.RawSyscall6(trap, a1, a2, a3, a4, a5, a6)
+}