users: Character vectors of users to be added to list.
name: Name of new list to create.
description: Optional, description of list (single character string).
private: Logical indicating whether created list should be private. Defaults to false, meaning the list would be public. Not applicable if list already exists.
destroy: Logical indicating whether to delete a list. Either list_id or slug must be provided if destroy = TRUE.
list_id: Optional, numeric ID of list.
slug: Optional, list slug.
token: Use this to override authentication for a single API call. In many cases you are better off changing the default for all calls. See auth_as() for details.