fix github actions badge in README: since 850b00a only a simple "mave…

…n" action is used for building

also limit the badge and link to "master" branch

README.md

@@ -4,8 +4,7 @@ This is the [versions-maven-plugin](http://www.mojohaus.org/versions-maven-plugi
 
 [![Apache License, Version 2.0, January 2004](https://img.shields.io/github/license/mojohaus/versions-maven-plugin.svg?label=License)](http://www.apache.org/licenses/)
 [![Maven Central](https://img.shields.io/maven-central/v/org.codehaus.mojo/versions-maven-plugin.svg?label=Maven%20Central)](http://search.maven.org/#search%7Cgav%7C1%7Cg%3A%22org.codehaus.mojo%22%20AND%20a%3A%22versions-maven-plugin%22)
-[![Main](https://github.com/mojohaus/versions-maven-plugin/workflows/Main/badge.svg)](https://github.com/mojohaus/versions-maven-plugin/actions?query=workflow%3AMain)
-[![JDKBuilds](https://github.com/mojohaus/versions-maven-plugin/workflows/JDKBuilds/badge.svg)](https://github.com/mojohaus/versions-maven-plugin/actions?query=workflow%3AJDKBuilds)
+[![Build Status](https://github.com/mojohaus/versions-maven-plugin/workflows/GitHub%20CI/badge.svg?branch=master)](https://github.com/mojohaus/versions-maven-plugin/actions/workflows/maven.yml?query=branch%3Amaster)
 
 
 ## Contributing