Add link to Travis CI

Author: wojtekmaj

README.md

@@ -1,4 +1,4 @@
-[![npm](https://img.shields.io/npm/v/react-pdf.svg)](https://www.npmjs.com/package/react-pdf) ![downloads](https://img.shields.io/npm/dt/react-pdf.svg) ![build](https://travis-ci.com/wojtekmaj/react-pdf.svg?branch=master) ![dependencies](https://img.shields.io/david/wojtekmaj/react-pdf.svg) ![dev dependencies](https://img.shields.io/david/dev/wojtekmaj/react-pdf.svg) [![tested with jest](https://img.shields.io/badge/tested_with-jest-99424f.svg)](https://github.com/facebook/jest)
+[![npm](https://img.shields.io/npm/v/react-pdf.svg)](https://www.npmjs.com/package/react-pdf) ![downloads](https://img.shields.io/npm/dt/react-pdf.svg) [![build](https://travis-ci.com/wojtekmaj/react-pdf.svg?branch=master)](https://travis-ci.com/wojtekmaj/react-pdf) ![dependencies](https://img.shields.io/david/wojtekmaj/react-pdf.svg) ![dev dependencies](https://img.shields.io/david/dev/wojtekmaj/react-pdf.svg) [![tested with jest](https://img.shields.io/badge/tested_with-jest-99424f.svg)](https://github.com/facebook/jest)
 
 # React-PDF