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/Shopify/sarama/Makefile b/demo_test/vendor/github.com/Shopify/sarama/Makefile
new file mode 100644
index 0000000..c3b431a
--- /dev/null
+++ b/demo_test/vendor/github.com/Shopify/sarama/Makefile
@@ -0,0 +1,27 @@
+default: fmt get update test lint
+
+GO       := GO111MODULE=on GOPRIVATE=github.com/linkedin GOSUMDB=off go
+GOBUILD  := CGO_ENABLED=0 $(GO) build $(BUILD_FLAG)
+GOTEST   := $(GO) test -gcflags='-l' -p 3 -v -race -timeout 6m -coverprofile=profile.out -covermode=atomic
+
+FILES    := $(shell find . -name '*.go' -type f -not -name '*.pb.go' -not -name '*_generated.go' -not -name '*_test.go')
+TESTS    := $(shell find . -name '*.go' -type f -not -name '*.pb.go' -not -name '*_generated.go' -name '*_test.go')
+
+get:
+	$(GO) get ./...
+	$(GO) mod verify
+	$(GO) mod tidy
+
+update:
+	$(GO) get -u -v all
+	$(GO) mod verify
+	$(GO) mod tidy
+
+fmt:
+	gofmt -s -l -w $(FILES) $(TESTS)
+
+lint:
+	golangci-lint run
+
+test:
+	$(GOTEST) ./...