Added a few things...

Thanks for the wrapper!

It looks like something might be wrong with Docraptors SSL certificate.

To debug, I changed your original class to echo out the actual curl error message (Line 92) which clued me in.

Since I went that far, I added a new method setSecure to allow the user to choose a secure connection, and changed the class to use http by default.

Feel free to use if it helps. 

-Jason