Drop inactive badge from README.md

The Codeclimate is no longer.

Author: olleolleolle

README.md

@@ -1,7 +1,6 @@
 # bundler-audit
 
 [![CI](https://github.com/rubysec/bundler-audit/actions/workflows/ruby.yml/badge.svg)](https://github.com/rubysec/bundler-audit/actions/workflows/ruby.yml)
-[![Code Climate](https://codeclimate.com/github/rubysec/bundler-audit.svg)](https://codeclimate.com/github/rubysec/bundler-audit)
 [![Gem Version](https://badge.fury.io/rb/bundler-audit.svg)](https://badge.fury.io/rb/bundler-audit)
 
 * [Homepage](https://github.com/rubysec/bundler-audit#readme)