Remove obsolete Travis CI badge

Author: J0WI

matomo/content.md

@@ -1,6 +1,6 @@
 # Matomo (formerly Piwik)
 
-[![Build Status](https://travis-ci.org/matomo-org/docker.svg?branch=master)](https://travis-ci.org/matomo-org/docker) [Matomo](https://matomo.org/) (formerly Piwik) is the leading open-source analytics platform that gives you more than just powerful analytics:
+[Matomo](https://matomo.org/) (formerly Piwik) is the leading open-source analytics platform that gives you more than just powerful analytics:
 
 -	Free open-source software
 -	100% data ownership