Rename plugins to libs and update all file references

plugins/vendor/zbateson/mail-mime-parser/.php-cs-fixer.dist.php

@@ -1,15 +0,0 @@
-<?php
-/*
- * This document has been generated with
- * https://mlocati.github.io/php-cs-fixer-configurator/#version:3.0.0-rc.1|configurator
- * you can change this configuration by importing this file.
- *
- */
-
-$config = include 'vendor/zbateson/mb-wrapper/PhpCsFixer.php';
-
-return $config->setFinder(PhpCsFixer\Finder::create()
-    ->exclude('vendor')
-    ->in(__DIR__.'/src')
-    ->in(__DIR__.'/tests')
-    );