Remove unused badge

[skip CI]

Author: Byron

README.md

@@ -188,7 +188,6 @@ New BSD License.  See the LICENSE file.
 
 [![codecov](https://codecov.io/gh/gitpython-developers/GitPython/branch/master/graph/badge.svg)](https://codecov.io/gh/gitpython-developers/GitPython)
 [![Build Status](https://travis-ci.org/gitpython-developers/GitPython.svg)](https://travis-ci.org/gitpython-developers/GitPython)
-[![Code Climate](https://codeclimate.com/github/gitpython-developers/GitPython/badges/gpa.svg)](https://codeclimate.com/github/gitpython-developers/GitPython)
 [![Documentation Status](https://readthedocs.org/projects/gitpython/badge/?version=stable)](https://readthedocs.org/projects/gitpython/?badge=stable)
 [![Packaging status](https://repology.org/badge/tiny-repos/python:gitpython.svg)](https://repology.org/metapackage/python:gitpython/versions)