added Makefile

Makefile

@@ -0,0 +1,20 @@
+.PHONY: all test clean build install
+
+GOFLAGS ?= $(GOFLAGS:)
+
+all: install test
+
+build:
+	go build $(GOFLAGS) ./...
+
+install:
+	go get $(GOFLAGS) ./...
+
+test: install
+	go test $(GOFLAGS) ./...
+
+bench: install
+	go test -run=NONE -bench=. $(GOFLAGS) ./...
+
+clean:
+	go clean $(GOFLAGS) -i ./...