Update README.md

Author: cdimascio

README.md

@@ -1,6 +1,6 @@
 # py-readability-metrics
 
-![Travis Build](https://travis-ci.org/cdimascio/py-readability-metrics.svg?branch=master) ![Python](https://img.shields.io/badge/python-%203.4%20%7C%203.5%20%7C%203.6-blue.svg) [![Documentation Status](https://readthedocs.org/projects/py-readability-metrics/badge/?version=latest)](https://py-readability-metrics.readthedocs.io/en/latest/?badge=latest) [![wheel](https://img.shields.io/badge/wheel-yes-ff00c9.svg)](https://pypi.org/project/py-readability-metrics/) [![](https://img.shields.io/gitter/room/cdimascio-oss/community?color=%23eb205a)](https://gitter.im/cdimascio-oss/community)
+![Travis Build](https://travis-ci.org/cdimascio/py-readability-metrics.svg?branch=master) ![Python](https://img.shields.io/badge/python-3.x-blue.svg) [![Documentation Status](https://readthedocs.org/projects/py-readability-metrics/badge/?version=latest)](https://py-readability-metrics.readthedocs.io/en/latest/?badge=latest) [![wheel](https://img.shields.io/badge/wheel-yes-ff00c9.svg)](https://pypi.org/project/py-readability-metrics/) [![](https://img.shields.io/gitter/room/cdimascio-oss/community?color=%23eb205a)](https://gitter.im/cdimascio-oss/community)
  [![MIT license](https://img.shields.io/badge/License-MIT-green.svg)](https://lbesson.mit-license.org/)
 
 Score the _readability_ of text using popular readability metrics including: [Flesch Kincaid Grade Level](#flesch-kincaid-grade-level), [Flesch Reading Ease](#flesch-reading-ease), [Gunning Fog Index](#gunning-fog), [Dale Chall Readability](#dale-chall-readability), [Automated Readability Index (ARI)](#automated-readability-index-ari), [Coleman Liau Index](#coleman-liau-index), [Linsear Write](#linsear-write), [SMOG](#smog), and [SPACHE](#spache). 📗