Changed travis icon to SVG for us, poor souls with retina displays

Author: gabrielbull

README.md

@@ -1,7 +1,10 @@
 # ![PHPWord](https://raw.github.com/PHPOffice/PHPWord/develop/docs/images/phpword.png "PHPWord")
 
-[![Build Status](https://travis-ci.org/PHPOffice/PHPWord.png?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) [![License](https://poser.pugx.org/phpoffice/phpword/license.png)](https://packagist.org/packages/phpoffice/phpword)
+[![Build Status](https://travis-ci.org/PHPOffice/PHPWord.svg?branch=develop)](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)
+[![License](https://poser.pugx.org/phpoffice/phpword/license.png)](https://packagist.org/packages/phpoffice/phpword)
 
 
 PHPWord is a library written in pure PHP that provides a set of classes to write to and read from different document file formats. The current version of PHPWord supports Microsoft [Office Open XML](http://en.wikipedia.org/wiki/Office_Open_XML) (OOXML or OpenXML), OASIS [Open Document Format for Office Applications](http://en.wikipedia.org/wiki/OpenDocument) (OpenDocument or ODF), and [Rich Text Format](http://en.wikipedia.org/wiki/Rich_Text_Format) (RTF).