Changed travis branch in read me to master

Author: gabrielbull

README.md

@@ -1,6 +1,6 @@
 # ![PHPWord](https://raw.githubusercontent.com/PHPOffice/PHPWord/develop/docs/images/phpword.svg "PHPWord")
 
-[![Build Status](https://travis-ci.org/PHPOffice/PHPWord.svg?branch=develop)](https://travis-ci.org/PHPOffice/PHPWord)
+[![Build Status](https://travis-ci.org/PHPOffice/PHPWord.svg?branch=master)](https://travis-ci.org/PHPOffice/PHPWord)
 [![Latest Stable Version](https://poser.pugx.org/phpoffice/phpword/v/stable.png)](https://packagist.org/packages/phpoffice/phpword)
 [![Total Downloads](https://poser.pugx.org/phpoffice/phpword/downloads.png)](https://packagist.org/packages/phpoffice/phpword)
 [![Latest Unstable Version](https://poser.pugx.org/phpoffice/phpword/v/unstable.png)](https://packagist.org/packages/phpoffice/phpword)