Added config for php-cs-fixer

.gitignore

@@ -1,2 +1,4 @@
 /vendor/
 composer.lock
+.php_cs.cache
+

.php_cs

@@ -0,0 +1,28 @@
+<?php
+
+return Symfony\CS\Config\Config::create()
+    ->setUsingLinter(false)
+    ->setUsingCache(true)
+    ->level(Symfony\CS\FixerInterface::SYMFONY_LEVEL)
+    ->fixers([
+        'concat_with_spaces',
+        '-concat_without_spaces',
+        '-empty_return',
+        '-phpdoc_params',
+        '-phpdoc_separation',
+        '-phpdoc_to_comment',
+        '-spaces_cast',
+        '-blankline_after_open_tag',
+        // psr0 has weird issues with our PSR-4 layout, so deactivating it.
+        '-psr0',
+    ])
+    ->finder(
+        Symfony\CS\Finder\DefaultFinder::create()
+            ->name('*.php')
+            ->in(__DIR__)
+            ->notPath('phpunit.xml')
+            ->exclude([
+                'vendor',
+            ])
+    )
+;