Add reproducible build badge to README

Author: gredler

README.md

@@ -1,4 +1,4 @@
-# Okapi Barcode [![License](https://img.shields.io/badge/license-Apache%202-blue.svg)](http://www.apache.org/licenses/LICENSE-2.0.html) [![Maven Central](https://maven-badges.herokuapp.com/maven-central/uk.org.okapibarcode/okapibarcode/badge.svg)](https://maven-badges.herokuapp.com/maven-central/uk.org.okapibarcode/okapibarcode) [![Code Coverage](https://codecov.io/gh/woo-j/OkapiBarcode/branch/master/graph/badge.svg)](https://codecov.io/gh/woo-j/OkapiBarcode/branch/master)
+# Okapi Barcode [![License](https://img.shields.io/badge/license-Apache%202-blue.svg)](http://www.apache.org/licenses/LICENSE-2.0.html) [![Maven Central](https://maven-badges.herokuapp.com/maven-central/uk.org.okapibarcode/okapibarcode/badge.svg)](https://maven-badges.herokuapp.com/maven-central/uk.org.okapibarcode/okapibarcode) [![Code Coverage](https://codecov.io/gh/woo-j/OkapiBarcode/branch/master/graph/badge.svg)](https://codecov.io/gh/woo-j/OkapiBarcode/branch/master) [![Reproducible Builds](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/jvm-repo-rebuild/reproducible-central/master/content/uk/org/okapibarcode/okapibarcode/badge.json)](https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/uk/org/okapibarcode/okapibarcode/README.md)
 
 Okapi Barcode is an open-source barcode generator written entirely in Java,
 supporting over 50 encoding standards, including all ISO standards. Okapi