Add php-cs-fixer as tool to project

Installed according to best practice in README of php-cs-fixer

Author: Zombaya

.gitignore

@@ -9,6 +9,7 @@ test_services.json
 .idea
 .php_cs.cache
 .phpunit.result.cache
+.php-cs-fixer.cache
 atlassian-ide-plugin.xml
 aws-sdk-php.iml
 .DS_Store

.php-cs-fixer.dist.php

@@ -0,0 +1,24 @@
+<?php
+
+$finder = PhpCsFixer\Finder::create()
+    ->in([
+        __DIR__ . '/src',
+        __DIR__ . '/tests',
+    ])
+    ->exclude([
+        'data'
+    ])
+;
+
+return (new PhpCsFixer\Config())
+    ->setRules([
+        '@PSR12' => true,
+        'visibility_required' => [
+            'elements' => [
+                'property',
+                'method',
+            ],
+        ]
+    ])
+    ->setFinder($finder)
+;

tools/php-cs-fixer/.gitignore

@@ -0,0 +1 @@
+.php-cs-fixer.cache

tools/php-cs-fixer/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "friendsofphp/php-cs-fixer": "^3.8.0"
+    }
+}