Upsert Category Trees

Upserts *Category Trees*. This single endpoint updates and creates category trees. If a tree object contains an ID, it is processed as an update operation using that ID. If you do not provide an ID, a new tree is created. The category tree `name` field is required to create trees, but is not required on the update. **Usage Notes** * `channel_id` is required to create a *Category Tree*. You can assign one `channel_id` to one category tree.