Update badge formatting

README.md

@@ -6,7 +6,7 @@
 
 [![Discord](https://img.shields.io/discord/481002907366588416.svg)](https://discord.gg/E3YrVtG)
 [![PyPI](https://badge.fury.io/py/mythril.svg)](https://pypi.python.org/pypi/mythril)
-[![Read the Docs](https://readthedocs.org/projects/mythril-classic/badge/?version=master&style=plastic)](https://mythril-classic.readthedocs.io/en/master/)
+[![Read the Docs](https://readthedocs.org/projects/mythril-classic/badge/?version=master)](https://mythril-classic.readthedocs.io/en/master/)
 ![Master Build Status](https://img.shields.io/circleci/project/github/ConsenSys/mythril-classic/master.svg)
 [![Waffle.io - Columns and their card count](https://badge.waffle.io/ConsenSys/mythril-classic.svg?columns=In%20Progress)](https://waffle.io/ConsenSys/mythril-classic/)
 [![Sonarcloud - Maintainability](https://sonarcloud.io/api/project_badges/measure?project=mythril&metric=sqale_rating)](https://sonarcloud.io/dashboard?id=mythril)