README: remove link to analysis reports

The analysis reports are currently very out-of-date, with the last update having been run in February 2018.

I'm not (yet) sure whether those will be republished.

Author: jrfnl

README.md

@@ -4,7 +4,6 @@ PHP_CodeSniffer is a set of two PHP scripts; the main `phpcs` script that tokeni
 
 [![Build Status](https://github.com/squizlabs/PHP_CodeSniffer/workflows/Validate/badge.svg?branch=master)](https://github.com/squizlabs/PHP_CodeSniffer/actions)
 [![Build Status](https://github.com/squizlabs/PHP_CodeSniffer/workflows/Test/badge.svg?branch=master)](https://github.com/squizlabs/PHP_CodeSniffer/actions)
-[![Code consistency](http://squizlabs.github.io/PHP_CodeSniffer/analysis/squizlabs/PHP_CodeSniffer/grade.svg)](http://squizlabs.github.io/PHP_CodeSniffer/analysis/squizlabs/PHP_CodeSniffer)
 [![Join the chat at https://gitter.im/squizlabs/PHP_CodeSniffer](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/squizlabs/PHP_CodeSniffer?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 ## Requirements