private function post($endpoint, array $data)
 {
     $client = new Client();
     $response = $client->post($this->getUrl($endpoint), ['auth' => $this->auth->getBasicHeaderArray(), 'headers' => ['Accept' => 'application/vnd.github.v3+json'], 'json' => $data]);
     $this->rateLimitRemaining = (int) $response->getHeaderLine('X-RateLimit-Remaining');
     return json_decode($response->getBody()->getContents(), true);
 }