Allow usage of custom guzzle clients

Author: LKaemmerling

src/Models/Model.php

@@ -2,6 +2,7 @@
 
 namespace LKDev\HetznerCloud\Models;
 
+use GuzzleHttp\Client;
 use LKDev\HetznerCloud\Clients\GuzzleClient;
 use LKDev\HetznerCloud\HetznerAPIClient;
 
@@ -20,7 +21,7 @@ abstract class Model
      * Model constructor.
      * @param GuzzleClient $httpClient
      */
-    public function __construct(GuzzleClient $httpClient = null)
+    public function __construct(Client $httpClient = null)
     {
         $this->httpClient = $httpClient == null ? HetznerAPIClient::$instance->getHttpClient() : $httpClient;
     }
@@ -32,4 +33,4 @@ public function __construct(GuzzleClient $httpClient = null)
     public static function parse($input)
     {
     }
-}
+}