add Makefile

Makefile

@@ -0,0 +1,14 @@
+SHELL := /bin/bash
+
+.PHONY: all check test
+
+all: check test
+
+check:
+	go build && go vet && gofmt -s -l .
+
+test:
+	go test -v -coverprofile coverage.out && go tool cover -html coverage.out -o coverage.html
+
+bench:
+	go test -bench .