Add Makefile for release using ghr

Makefile

@@ -0,0 +1,43 @@
+OWNER      = gongo
+REPOSITORY = 9t
+
+COMMAND  = 9t
+MAIN_DIR = cmd/9t
+VERSION  = $(shell grep "const Version " $(MAIN_DIR)/version.go | sed -E 's/.*"(.+)"$$/\1/')
+
+TOP       = $(shell pwd)
+BUILD_DIR = $(TOP)/pkg
+DIST_DIR  = $(TOP)/dist
+
+XC_ARCH   = "386 amd64"
+XC_OS     = "darwin linux windows"
+XC_OUTPUT = "$(BUILD_DIR)/{{.OS}}_{{.Arch}}/{{.Dir}}"
+
+
+setup:
+	gox -os $(XC_OS) -arch $(XC_ARCH) -build-toolchain
+	go get github.com/tcnksm/ghr
+
+build:
+	rm -rf $(BUILD_DIR)
+	mkdir $(BUILD_DIR)
+	gox -os $(XC_OS) -arch $(XC_ARCH) -output $(XC_OUTPUT) ./$(MAIN_DIR)
+
+dist: build
+	rm -rf $(DIST_DIR)
+	mkdir $(DIST_DIR)
+
+	@for dir in $$(find $(BUILD_DIR) -mindepth 1 -maxdepth 1 -type d); do \
+		platform=$$(basename $$dir) ; \
+		archive=$(COMMAND)_$(VERSION)_$$platform ;\
+		zip -j $(DIST_DIR)/$$archive.zip $$dir/* ;\
+	done
+
+	@pushd $(DIST_DIR) ; shasum -a 256 *.zip > ./SHA256SUMS ; popd
+
+release:
+	ghr -u $(OWNER) -r $(REPOSITORY) $(VERSION) $(DIST_DIR)
+
+clean:
+	rm -rf $(BUILD_DIR)
+	rm -rf $(DIST_DIR)