Use svg instead of png to get better image quality

README.md

@@ -99,7 +99,7 @@ We are grateful if you can share the Job Description with your friends and colle
 The Piwik project uses an ever-expanding comprehensive set of thousands of unit and integration tests and dozens of system [tests](https://github.com/piwik/piwik/tree/master/tests),
  running on the hosted distributed continuous integration platform Travis-CI.
 
-Build status (master branch) [![Build Status](https://travis-ci.org/piwik/piwik.png?branch=master)](https://travis-ci.org/piwik/piwik) - Screenshot tests Build  [![Build Status](https://travis-ci.org/piwik/piwik-ui-tests.png?branch=master)](https://travis-ci.org/piwik/piwik-ui-tests)
+Build status (master branch) [![Build Status](https://travis-ci.org/piwik/piwik.svg?branch=master)](https://travis-ci.org/piwik/piwik) - Screenshot tests Build  [![Build Status](https://travis-ci.org/piwik/piwik-ui-tests.svg?branch=master)](https://travis-ci.org/piwik/piwik-ui-tests)
 
 Code Coverage: [![Coverage Status](https://coveralls.io/repos/piwik/piwik/badge.png?branch=master)](https://coveralls.io/r/piwik/piwik?branch=master)