Change badge extension to SVG

Author: Anatol Broder

README.md

@@ -6,7 +6,7 @@ continuous integration with a PHP project.
 
 Here is a sample status icon showing the state of the master branch.
 
-[![Build Status](https://secure.travis-ci.org/travis-ci/travis-ci-php-example.png?branch=master)](http://travis-ci.org/travis-ci/travis-ci-php-example)
+[![Build Status](https://travis-ci.org/travis-ci/travis-ci-php-example.svg?branch=master)](http://travis-ci.org/travis-ci/travis-ci-php-example)
 
 In order to run this project just fork it on github.com and then [enable](http://about.travis-ci.org/docs/user/getting-started/)
 your fork on your [travis-ci profile](http://travis-ci.org/profile). Every push will then trigger a new build on Travis CI.