Update README.md

Author: Throyer

README.md

@@ -79,6 +79,7 @@ $ mvn jacoco:report
 ```
 
 ## Tests
+[![Coverage Status](https://coveralls.io/repos/github/Throyer/springboot-api-crud/badge.svg?branch=master)](https://coveralls.io/repos/github/Throyer/springboot-api-crud/badge.svg?branch=master)
 
 ## Running a specific test
 use the parameter `-Dtest=<class>#<method>`