Update README.md

Author: JeroenDeDauw

README.md

@@ -5,7 +5,6 @@
 [![Code Coverage](https://scrutinizer-ci.com/g/wmde/WikibaseDataModel/badges/coverage.png?b=master)](https://scrutinizer-ci.com/g/wmde/WikibaseDataModel/?branch=master)
 [![Dependency Status](https://www.versioneye.com/php/wikibase:data-model/dev-master/badge.svg)](https://www.versioneye.com/php/wikibase:data-model/dev-master)
 [![Download count](https://poser.pugx.org/wikibase/data-model/d/total.png)](https://packagist.org/packages/wikibase/data-model)
-[![Reference Status](https://www.versioneye.com/php/wikibase:data-model/reference_badge.svg)](https://www.versioneye.com/php/wikibase:data-model/references)
 [![License](https://poser.pugx.org/wikibase/data-model/license.svg)](https://packagist.org/packages/wikibase/data-model)
 
 [![Latest Stable Version](https://poser.pugx.org/wikibase/data-model/version.png)](https://packagist.org/packages/wikibase/data-model)