If you don't have access to php.ini, adding this code (after your $ch = curl_init(); line) works for me:
$certificate_location = "C:\Program Files (x86)\EasyPHP-Devserver-16.1\ca-bundle.crt"; // modify this line accordingly (may need to be absolute)
curl_setopt($ch, CURLOPT_CAINFO, $certificate_location);
curl_setopt($ch, CURLOPT_CAPATH, $certificate_location);
Then, you will just need to download ca-bundle.crt and save it to location you specified in $certificate_location.
Hope this works!!