try adding code coverage

Author: cowtowncoder

README.md

@@ -12,6 +12,8 @@ Naming of classes uses word 'JSON' in many places even though there is no actual
 [![Build Status](https://travis-ci.org/FasterXML/jackson-databind.svg?branch=master)](https://travis-ci.org/FasterXML/jackson-databind) [![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.fasterxml.jackson.core/jackson-databind/badge.svg)](https://maven-badges.herokuapp.com/maven-central/com.fasterxml.jackson.core/jackson-databind)
 [![Javadoc](https://javadoc-emblem.rhcloud.com/doc/com.fasterxml.jackson.core/jackson-databind/badge.svg)](http://www.javadoc.io/doc/com.fasterxml.jackson.core/jackson-databind)
 
+[![Coverage Status](https://coveralls.io/repos/github/FasterXML/jackson-databin/badge.svg?branch=master)](https://coveralls.io/github/FasterXML/jackson-databin?branch=master)
+
 -----
 
 # Get it!