improved code styles #158 (#172)

* use php-cs-fixer instead of phpcodesniffer
* updated scrutinizer config
* adjusted code yules to all files
* updated CONTRIBUTING guidelines

src/Repository/Query/UserQuery.php

@@ -14,7 +14,6 @@ namespace App\Repository\Query;
  */
 class UserQuery extends VisibilityQuery
 {
-
     /**
      * @var string
      */
@@ -34,9 +33,10 @@ class UserQuery extends VisibilityQuery
      */
     public function setRole($role)
     {
-        if (strpos($role, 'ROLE_') !== false || $role === null) {
+        if (false !== strpos($role, 'ROLE_') || null === $role) {
             $this->role = $role;
         }
+
         return $this;
     }
 }