Added an PHP CS fixer config file and applied it to files.

We now use the same the same style as the symfony project, and it allows us to simply fix the style by executing php_cs_fixer fix in the project root.

src/Entity/Devices/Device.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony)
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
  *
  * Copyright (C) 2019 Jan Böhmer (https://github.com/jbtronics)
  *
@@ -17,7 +17,6 @@
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
- *
  */
 
 declare(strict_types=1);
@@ -52,7 +51,6 @@ declare(strict_types=1);
 
 namespace App\Entity\Devices;
 
-use App\Entity\Attachments\AttachmentTypeAttachment;
 use App\Entity\Attachments\DeviceAttachment;
 use App\Entity\Base\PartsContainingDBElement;
 use Doctrine\Common\Collections\Collection;
@@ -66,7 +64,6 @@ use Doctrine\ORM\Mapping as ORM;
  */
 class Device extends PartsContainingDBElement
 {
-
     /**
      * @var Collection|DeviceAttachment[]
      * @ORM\OneToMany(targetEntity="App\Entity\Attachments\DeviceAttachment", mappedBy="element", cascade={"persist", "remove"}, orphanRemoval=true)
@@ -137,8 +134,6 @@ class Device extends PartsContainingDBElement
      *  Set the order quantity.
      *
      * @param int $new_order_quantity the new order quantity
-     *
-     * @return self
      */
     public function setOrderQuantity(int $new_order_quantity): self
     {
@@ -154,8 +149,6 @@ class Device extends PartsContainingDBElement
      *  Set the "order_only_missing_parts" attribute.
      *
      * @param bool $new_order_only_missing_parts the new "order_only_missing_parts" attribute
-     *
-     * @return self
      */
     public function setOrderOnlyMissingParts(bool $new_order_only_missing_parts): self
     {