Fix readme

README.md

@@ -1,7 +1,7 @@
 ## Bowser
 A browser detector. Because sometimes, there is no other way, and not even good modern browsers always provide good feature detection mechanisms.
 
-[![Build Status](https://travis-ci.org/lancedikson/bowser.svg?branch=master)](https://travis-ci.org/lancedikson/bowser/) [![Greenkeeper badge](https://badges.greenkeeper.io/lancedikson/bowser.svg)](https://greenkeeper.io/)
+[![Build Status](https://travis-ci.org/lancedikson/bowser.svg?branch=master)](https://travis-ci.org/lancedikson/bowser/) [![Greenkeeper badge](https://badges.greenkeeper.io/lancedikson/bowser.svg)](https://greenkeeper.io/)[![Coverage Status](https://coveralls.io/repos/github/lancedikson/bowser/badge.svg?branch=master)](https://coveralls.io/github/lancedikson/bowser?branch=master)
 
 # Contents
 - [Overview](#overview)
@@ -129,10 +129,14 @@ Thus, you can define OS or platform specific rules and they will have more prior
 More of API and possibilities you will find in the `docs` folder.
 
 # Contributing
+
+We're always open to pull requests or code reviews. Everyone can become a permanent contributor. Just ping @lancedikson in the issues or on Twitter ❤️
+
 If you'd like to contribute a change to bowser, modify the files in `src/`, then run the following (you'll need node + npm installed):
 
 ``` sh
-$ npm install #build
+$ npm install
+$ npm run build #build
 $ npm test #run tests
 $ npm run lint #check lint rules
 ```