add makefile

Makefile

@@ -0,0 +1,19 @@
+GOFILES=$(wildcard *.go)
+PROG=nunbot
+#set variables
+GIT_COMMIT := $(shell git rev-list -1 HEAD)
+GIT_TAG := $(shell git describe --tags | cut -d- -f1)
+ifeq ($(PREFIX),) # PREFIX is environment variable, but if it is not set, then set default value
+	PREFIX := /usr/local
+endif
+
+$(PROG): $(GOFILES)
+	go build -ldflags "-X main.GitCommit=$(GIT_COMMIT) -X main.GitTag=$(GIT_TAG)"
+
+clean:
+	rm -f nunbot
+
+install: $(NUNBOT)
+	install -d $(DESTDIR)$(PREFIX)/bin
+	install -m 755 $(PROG) $(DESTDIR)$(PREFIX)/bin
+