Update README.md

Added coveralls badge

Author: keilw

README.md

@@ -13,7 +13,9 @@ http://javamoney.github.io/ri.html
 This module is licenced under the the [Apache 2 Licence](https://www.apache.org/licenses/LICENSE-2.0.html).
 
 [![Maven Central](https://maven-badges.herokuapp.com/maven-central/org.javamoney/moneta/badge.svg)](https://maven-badges.herokuapp.com/maven-central/org.javamoney/moneta)
-[![Build Status](https://api.travis-ci.org/JavaMoney/jsr354-ri.png?branch=master)](https://travis-ci.org/JavaMoney/jsr354-ri) [![License](http://img.shields.io/badge/license-Apache2-red.svg)](http://opensource.org/licenses/apache-2.0)
+[![Build Status](https://api.travis-ci.org/JavaMoney/jsr354-ri.png?branch=master)](https://travis-ci.org/JavaMoney/jsr354-ri) 
+[![Coverage Status](https://coveralls.io/repos/JavaMoney/jsr354-ri/badge.svg?branch=master)](https://coveralls.io/r/JavaMoney/jsr354-ri?branch=master)
+[![License](http://img.shields.io/badge/license-Apache2-red.svg)](http://opensource.org/licenses/apache-2.0)
 [![Reference Status](https://www.versioneye.com/java/org.javamoney:moneta/reference_badge.svg?style=flat)](https://www.versioneye.com/java/org.javamoney:moneta/references)
 
 [![Built with Maven](http://maven.apache.org/images/logos/maven-feather.png)](http://maven.org/)