Added authentication system and field for user to Torrent model.
Creating a new torrent record now associates it with the current user.
No error handling is done yet, so it breaks if user isn't logged in.

Also implemented retrieve_queue, which runs a query for all torrents
linked to user matching user_id, dumps them to json, then returns the
json string. (ex. http://localhost:8000/api/request_queue/{user_id}/)

^ Additional checks should be added (like client app id) to enhance
security.