Fixed pagination for getUserLikes() method 

For some odd reason the Instagram API returns `max_liked_id` and `next_max_like_id` instead of `max_id` and `next_max_id` that seems to be used for the other pagination situations. My updates here simply look these `_like_` attributes in the event the normal ones are not set.

Previously using a `do-while` loop to paginate through `getUserLikes()` was producing an endless loop for me and never actually parsing the next page of results. It now paginates correctly and I have no issue.