Update coding style to include PSR-12, among other options

This also includes heavy use of slevomat/coding-standard to apply
various checks to the code, based on maintainer (me) preference.

src/Provider/Node/RandomNodeProvider.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * This file is part of the ramsey/uuid library
  *
@@ -7,31 +8,25 @@
  *
  * @copyright Copyright (c) Ben Ramsey <ben@benramsey.com>
  * @license http://opensource.org/licenses/MIT MIT
- * @link https://benramsey.com/projects/ramsey-uuid/ Documentation
- * @link https://packagist.org/packages/ramsey/uuid Packagist
- * @link https://github.com/ramsey/uuid GitHub
  */
 
+declare(strict_types=1);
+
 namespace Ramsey\Uuid\Provider\Node;
 
-use Exception;
 use Ramsey\Uuid\Provider\NodeProviderInterface;
 
 /**
- * RandomNodeProvider provides functionality to generate a random node ID, in
- * the event that the node ID could not be obtained from the host system
+ * RandomNodeProvider generates a random node ID
  *
- * @link http://tools.ietf.org/html/rfc4122#section-4.5
+ * @link http://tools.ietf.org/html/rfc4122#section-4.5 RFC 4122, § 4.5: Node IDs that Do Not Identify the Host
  */
 class RandomNodeProvider implements NodeProviderInterface
 {
     /**
-     * Returns the system node ID
-     *
-     * @return string System node ID as a hexadecimal string
-     * @throws Exception if it was not possible to gather sufficient entropy
+     * @inheritDoc
      */
-    public function getNode(): string
+    public function getNode()
     {
         $nodeBytes = random_bytes(6);