Update version info in README

Author: robertrossmann

README.md

@@ -54,5 +54,5 @@ This software is licensed under the **BSD-3-Clause License**. See the [LICENSE](
 [eslint-url]: http://eslint.org
 [travis-badge]: https://travis-ci.org/strvcom/js-coding-standards.svg
 [travis-url]: https://travis-ci.org/strvcom/js-coding-standards
-[eslint-version]: https://img.shields.io/badge/ESLint->=3.8.0-brightgreen.svg
+[eslint-version]: https://img.shields.io/badge/ESLint->=3.9.1-brightgreen.svg
 [eslint-fixing]: http://eslint.org/docs/user-guide/command-line-interface#fix