Function to create a label.
create_label(name, label_list_visibility = c("hide", "show", "show_unread"),
message_list_visibility = c("hide", "show"), user_id = "me")name to give to the new label
The visibility of the label in the label list in the Gmail web interface.
The visibility of messages with this label in the message list in the Gmail web interface.
gmail user_id to access, special value of 'me' indicates the authenticated user.
https://developers.google.com/gmail/api/v1/reference/users/labels/create
Other label: delete_label,
labels, label,
update_label