Update README.md

Author: mvcisback

README.md

@@ -11,7 +11,8 @@
 [![codecov](https://codecov.io/gh/mvcisback/py-aiger/branch/master/graph/badge.svg)](https://codecov.io/gh/mvcisback/py-aiger)
 [![Updates](https://pyup.io/repos/github/mvcisback/py-aiger/shield.svg)](https://pyup.io/repos/github/mvcisback/py-aiger/)
 
-[![PyPI version](https://badge.fury.io/py/py-aiger.svg)](https://badge.fury.io/py/py-aiger)[![PyPI license](https://img.shields.io/pypi/l/py-aiger.svg)](https://pypi.python.org/pypi/py-aiger/)
+[![PyPI version](https://badge.fury.io/py/py-aiger.svg)](https://badge.fury.io/py/py-aiger)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![DOI](https://zenodo.org/badge/130783753.svg)](https://zenodo.org/badge/latestdoi/130783753)
 
 # Table of Contents