Add Codacy Badge

- Add assimp to codacy
- Add batch to readme

Readme.md

@@ -8,6 +8,7 @@ A library to import and export various 3d-model-formats including scene-post-pro
   <img alt="Coverity Scan Build Status"
        src="https://scan.coverity.com/projects/5607/badge.svg"/>
 </a>
+[![Codacy Badge](https://app.codacy.com/project/badge/Grade/9973693b7bdd4543b07084d5d9cf4745)](https://www.codacy.com/gh/assimp/assimp/dashboard?utm_source=github.com&amp;utm_medium=referral&amp;utm_content=assimp/assimp&amp;utm_campaign=Badge_Grade)
 [![Coverage Status](https://coveralls.io/repos/github/assimp/assimp/badge.svg?branch=master)](https://coveralls.io/github/assimp/assimp?branch=master)
 [![Join the chat at https://gitter.im/assimp/assimp](https://badges.gitter.im/assimp/assimp.svg)](https://gitter.im/assimp/assimp?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/assimp/assimp.svg)](http://isitmaintained.com/project/assimp/assimp "Average time to resolve an issue")