Add -v flag to print version

Makefile

@@ -26,8 +26,7 @@ doc: $(DOCS)
 
 kiln: $(GOSRC)
 	$(GO) build $(GOFLAGS) \
-		-ldflags "-X main.Prefix=$(PREFIX) \
-		-X main.Version=$(VERSION)" \
+		-ldflags "-X main.Version=$(VERSION)" \
 		-o $@
 
 clean:

main.go

@@ -11,16 +11,27 @@ import (
 	"strings"
 )
 
+var (
+	Version string
+)
+
 func main() {
 	var (
-		task   string
-		config string
+		task    string
+		config  string
+		version bool
 	)
 
 	flag.StringVar(&task, "t", "all", "the task to run")
 	flag.StringVar(&config, "c", "config.toml", "the configuration file to use")
+	flag.BoolVar(&version, "v", false, "print version")
 	flag.Parse()
 
+	if version {
+		fmt.Println("kiln", Version)
+		return
+	}
+
 	// Load config
 	cfg, err := LoadConfig(config)
 	if err != nil {