Update request methods for onFocus and onSession from PUT to POST to match documentation

Author: norkunas

src/Devices.php

@@ -147,7 +147,7 @@ public function onSession($id, array $data)
             ->setAllowedTypes('sdk', 'string')
             ->resolve($data);
 
-        return $this->api->request('PUT', '/players/' . $id . '/on_session', [
+        return $this->api->request('POST', '/players/' . $id . '/on_session', [
             'headers' => [
                 'Content-Type' => 'application/json',
             ],
@@ -207,7 +207,7 @@ public function onFocus($id, array $data)
             ->setAllowedTypes('active_time', 'int')
             ->resolve($data);
 
-        return $this->api->request('PUT', '/players/' . $id . '/on_focus', [
+        return $this->api->request('POST', '/players/' . $id . '/on_focus', [
             'headers' => [
                 'Content-Type' => 'application/json',
             ],