Update README.md

Removed the Coveralls badge, since the integration is long gone.

Author: iSnow

README.md

@@ -1,7 +1,6 @@
 # tableschema-java
 
 [![Build Status](https://travis-ci.org/frictionlessdata/tableschema-java.svg?branch=master)](https://travis-ci.org/frictionlessdata/tableschema-java)
-[![Coverage Status](https://coveralls.io/repos/github/frictionlessdata/tableschema-java/badge.svg?branch=master)](https://coveralls.io/github/frictionlessdata/tableschema-java?branch=master)
 [![License](https://img.shields.io/github/license/frictionlessdata/tableschema-java.svg)](https://github.com/frictionlessdata/tableschema-java/blob/master/LICENSE)
 [![Release](https://img.shields.io/jitpack/v/github/frictionlessdata/tableschema-java)](https://jitpack.io/#frictionlessdata/tableschema-java)
 [![Codebase](https://img.shields.io/badge/codebase-github-brightgreen)](https://github.com/frictionlessdata/tableschema-java)