Update shields/badges in the README.md (#28)

Author: Rolf-Smit

README.md

@@ -1,4 +1,5 @@
-[![Gradle Plugin Portal](https://img.shields.io/maven-metadata/v/https/plugins.gradle.org/m2/org.neotech.plugin/android-root-coverage-plugin/maven-metadata.xml.svg?label=Plugin%20portal)](https://plugins.gradle.org/plugin/org.neotech.plugin.rootcoverage)
+[![Gradle Plugin Portal](https://img.shields.io/maven-metadata/v/https/plugins.gradle.org/m2/nl.neotech.plugin/android-root-coverage-plugin/maven-metadata.xml.svg?label=Gradle%20Plugin%20Portal)](https://plugins.gradle.org/plugin/nl.neotech.plugin.rootcoverage)
+[![Maven Central](https://img.shields.io/maven-central/v/nl.neotech.plugin/android-root-coverage-plugin?label=Maven%20Central)](https://search.maven.org/artifact/nl.neotech.plugin/android-root-coverage-plugin)
 [![Build status](https://travis-ci.com/NeoTech-Software/Android-Root-Coverage-Plugin.svg?branch=master)](https://travis-ci.com/NeoTech-Software/Android-Root-Coverage-Plugin/)
 
 # Android-Root-Coverage-Plugin