Add release script

Author: Takumasa Sakao

Makefile

@@ -1,6 +1,17 @@
+.PHONY: prepare install release
+
+ARTIFACTS_DIR=artifacts/${VERSION}
+GITHUB_USERNAME=sachaos
+
 prepare:
 	go get github.com/gobuffalo/packr/packr
 	go generate github.com/sachaos/go-life/preset
 
 install: prepare
 	go install
+
+release: prepare
+	GOOS=windows GOARCH=amd64 go build -o $(ARTIFACTS_DIR)/go-life_windows_amd64
+	GOOS=darwin GOARCH=amd64 go build -o $(ARTIFACTS_DIR)/go-life_darwin_amd64
+	GOOS=linux GOARCH=amd64 go build -o $(ARTIFACTS_DIR)/go-life_linux_amd64
+	ghr -u $(GITHUB_USERNAME) -t $(shell cat github_token) --replace ${VERSION} $(ARTIFACTS_DIR)