Update coverage badge

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[skip Scrutinizer]

Author: troosan

README.md

@@ -3,7 +3,7 @@
 [![Latest Stable Version](https://poser.pugx.org/phpoffice/phpword/v/stable.png)](https://packagist.org/packages/phpoffice/phpword)
 [![Build Status](https://travis-ci.org/PHPOffice/PHPWord.svg?branch=master)](https://travis-ci.org/PHPOffice/PHPWord)
 [![Code Quality](https://scrutinizer-ci.com/g/PHPOffice/PHPWord/badges/quality-score.png?s=b5997ce59ac2816b4514f3a38de9900f6d492c1d)](https://scrutinizer-ci.com/g/PHPOffice/PHPWord/)
-[![Code Coverage](https://scrutinizer-ci.com/g/PHPOffice/PHPWord/badges/coverage.png?s=742a98745725c562955440edc8d2c39d7ff5ae25)](https://scrutinizer-ci.com/g/PHPOffice/PHPWord/)
+[![Coverage Status](https://coveralls.io/repos/github/PHPOffice/PHPWord/badge.svg?branch=develop)](https://coveralls.io/github/PHPOffice/PHPWord?branch=develop)
 [![Total Downloads](https://poser.pugx.org/phpoffice/phpword/downloads.png)](https://packagist.org/packages/phpoffice/phpword)
 [![License](https://poser.pugx.org/phpoffice/phpword/license.png)](https://packagist.org/packages/phpoffice/phpword)
 [![Join the chat at https://gitter.im/PHPOffice/PHPWord](https://img.shields.io/badge/GITTER-join%20chat-green.svg)](https://gitter.im/PHPOffice/PHPWord)