feat(cli): Add --version flag (#572)

cmd/anubis/main.go

@@ -67,6 +67,7 @@ var (
 	ogCacheConsiderHost      = flag.Bool("og-cache-consider-host", false, "enable or disable the use of the host in the Open Graph tag cache")
 	extractResources         = flag.String("extract-resources", "", "if set, extract the static resources to the specified folder")
 	webmasterEmail           = flag.String("webmaster-email", "", "if set, displays webmaster's email on the reject page for appeals")
+	versionFlag              = flag.Bool("version", false, "print Anubis version")
 )
 
 func keyFromHex(value string) (ed25519.PrivateKey, error) {
@@ -202,6 +203,11 @@ func main() {
 	flagenv.Parse()
 	flag.Parse()
 
+	if *versionFlag {
+		fmt.Println("Anubis", anubis.Version)
+		return
+	}
+
 	internal.InitSlog(*slogLevel)
 
 	if *extractResources != "" {