Page only 50 items at once

Closes #37

Author: GrahamCampbell

src/ResultPager.php

@@ -98,7 +98,7 @@ public function fetchAll(ApiInterface $api, $method, array $parameters = [])
         $perPage = $api->getPerPage();
 
         // set parameters per_page to max to minimize number of requests
-        $api->setPerPage(100);
+        $api->setPerPage(50);
 
         try {
             $result = $this->fetch($api, $method, $parameters)['values'];