added systemd service files

README.md

@@ -3,6 +3,7 @@ tunasync
 
 [![Build Status](https://travis-ci.org/tuna/tunasync.svg?branch=dev)](https://travis-ci.org/tuna/tunasync)
 [![Coverage Status](https://coveralls.io/repos/github/tuna/tunasync/badge.svg?branch=dev)](https://coveralls.io/github/tuna/tunasync?branch=dev)
+![GPLv3](https://img.shields.io/badge/license-GPLv3-blue.svg)
 
 ## Design