Update README.md

Author: cddmp

README.md

@@ -6,6 +6,7 @@
 <img src="https://img.shields.io/badge/python-3.6-blue.svg"/>
 <img src="https://img.shields.io/badge/python-3.7-blue.svg"/>
 <img src="https://img.shields.io/badge/python-3.8-blue.svg"/>
+<img src="https://img.shields.io/badge/python-3.9-blue.svg"/>
 <img src="https://img.shields.io/badge/License-GPLv3-green.svg"/>
 </p>