Various improvements.

Makefile

@@ -0,0 +1,15 @@
+APP_EXAMPLE := triplex-example
+
+.PHONY: test build-example run-example fmt
+
+test:
+	go test ./...
+
+build-example:
+	go build -o bin/$(APP_EXAMPLE) ./cmd/$(APP_EXAMPLE)
+
+run-example:
+	go run ./cmd/$(APP_EXAMPLE)
+
+fmt:
+	gofmt -w ./serial/*.go ./cmd/$(APP_EXAMPLE)/*.go