Update build status badge

Author: fgrosse

README.md

@@ -1,7 +1,7 @@
 PHPASN1
 =======
 
-[![Build Status](https://secure.travis-ci.org/fgrosse/PHPASN1.png?branch=master)](http://travis-ci.org/fgrosse/PHPASN1)
+[![Build Status](https://github.com/fgrosse/PHPASN1/actions/workflows/phpunit.yml/badge.svg)](https://github.com/fgrosse/PHPASN1/actions/workflows/phpunit.yml)
 [![PHP 7 ready](http://php7ready.timesplinter.ch/fgrosse/PHPASN1/badge.svg)](https://travis-ci.org/fgrosse/PHPASN1)
 [![Coverage Status](https://coveralls.io/repos/fgrosse/PHPASN1/badge.svg?branch=master&service=github)](https://coveralls.io/github/fgrosse/PHPASN1?branch=master)