Update build status badge

Author: plamentotev

README.md

@@ -1,7 +1,7 @@
 Plexus-IO
 =========
 
-[![Build Status](https://travis-ci.org/codehaus-plexus/plexus-io.svg?branch=master)](https://travis-ci.org/codehaus-plexus/plexus-io)
+[![Build Status](https://github.com/codehaus-plexus/plexus-io/actions/workflows/maven.yml/badge.svg)](https://github.com/codehaus-plexus/plexus-io/actions/workflows/maven.yml)
 [![Maven Central](https://img.shields.io/maven-central/v/org.codehaus.plexus/plexus-io.svg?label=Maven%20Central)](https://search.maven.org/artifact/org.codehaus.plexus/plexus-io)
 
 The current master is now at https://github.com/codehaus-plexus/plexus-io