Update README.md

Danielhiversen · web-flow · commit a965598fd9e1 · 2018-10-10T13:16:02.000+02:00
diff --git a/README.md b/README.md
@@ -1,2 +1,4 @@
 # pySwitchbot [![Build Status](https://travis-ci.org/Danielhiversen/pySwitchbot.svg?branch=master)](https://travis-ci.org/Danielhiversen/pySwitchbot)
 Library to control Switchbot
+
+[Buy me a coffee :)](http://paypal.me/dahoiv)
