chore: add PHP CS Fixer configuration and update composer scripts

Author: wozozo

.php-cs-fixer.php

@@ -0,0 +1,15 @@
+<?php
+
+$finder = PhpCsFixer\Finder::create()
+    ->in([
+        __DIR__ . '/lib',
+        __DIR__ . '/tests',
+    ])
+    ->append([
+        __FILE__,
+        __DIR__ . '/init.php',
+        __DIR__ . '/build.php',
+    ]);
+
+$config = new PhpCsFixer\Config();
+return $config;

composer.json

@@ -33,9 +33,10 @@
     }
   },
   "scripts": {
-     "test": [
-       "phpcs --standard=PSR2 -n lib tests *.php",
-       "phpunit"
-     ]
+    "format": "PHP_CS_FIXER_IGNORE_ENV=1 php-cs-fixer fix --config=.php-cs-fixer.php lib tests *.php",
+    "test": [
+      "phpcs --standard=PSR2 -n lib tests *.php",
+      "phpunit"
+    ]
   }
 }