Fix PHP deprecation warnings

src/Exception/ApiException.php

@@ -9,7 +9,7 @@ class ApiException extends Exception {
     /** @var ResponseInterface $response */
     protected $response;
 
-    public function __construct( $message = "", ResponseInterface $response ) {
+    public function __construct( $message, ResponseInterface $response ) {
         $this->response = $response;
 
         parent::__construct( $message, $response->getStatusCode() );

src/V2/Pagination/IPaginatedEndpoint.php

@@ -30,5 +30,5 @@ function page( $page, $size = null );
      * @param callable $callback
      * @return void
      */
-    function batch( $parallelRequests = null, callable $callback );
+    function batch( $parallelRequests, $callback = null );
 }

src/V2/Pagination/PaginatedEndpoint.php

@@ -81,7 +81,7 @@ public function page( $page, $size = null ) {
      * @param callable $callback
      * @return void
      */
-    public function batch( $parallelRequests = null, callable $callback = null ) {
+    public function batch( $parallelRequests, $callback = null ) {
         /** @noinspection PhpParamsInspection */
         if( !isset( $callback ) && is_callable( $parallelRequests )) {
             $callback = $parallelRequests;

tests/Stubs/BulkEndpointStub.php

@@ -8,6 +8,12 @@
 
 class BulkEndpointStub extends EndpointStub implements IBulkEndpoint {
     use BulkEndpoint;
+
+    /** @var bool $supportsIdsAll */
+    protected $supportsIdsAll = false;
+
+    /** @var int $maxPageSize */
+    protected $maxPageSize = false;
 
     public function __construct( GW2Api $api, $supportsIdsAll, $maxPageSize ) {
         $this->supportsIdsAll = $supportsIdsAll;

tests/Stubs/PaginatedEndpointStub.php

@@ -9,6 +9,9 @@
 class PaginatedEndpointStub extends EndpointStub implements IPaginatedEndpoint {
     use PaginatedEndpoint;
 
+    /** @var int $maxPageSize */
+    protected $maxPageSize = false;
+
     public function __construct(  GW2Api $api, $maxPageSize = 10 ) {
         parent::__construct( $api );