chore: Add code climate badge on readme (shootismoke#276)

README.md

@@ -5,6 +5,7 @@ Know how many cigarettes you smoke based on the pollution of your location. :poo
 [![Travis (.org)](https://img.shields.io/travis/amaurymartiny/shoot-i-smoke.svg)](https://travis-ci.org/amaurymartiny/shoot-i-smoke)
 ![GitHub](https://img.shields.io/github/license/amaurymartiny/shoot-i-smoke.svg)
 [![David](https://img.shields.io/david/amaurymartiny/shoot-i-smoke.svg)](https://david-dm.org/amaurymartiny/shoot-i-smoke)
+[![Maintainability](https://api.codeclimate.com/v1/badges/9fc8ebb000978f14b6d0/maintainability)](https://codeclimate.com/github/amaurymartiny/shoot-i-smoke/maintainability)
 [![](https://img.shields.io/badge/Buy%20me%20a%20tree-%F0%9F%8C%B3-lightgreen)](https://offset.earth/amaurymartiny)
 [![Join the community on Spectrum](https://withspectrum.github.io/badge/badge.svg)](https://spectrum.chat/shootismoke)