Add spam role for a User

This endpoint allows the client to add the spam role to a user.

      The user associated with the API key must have any 'admin' or 'moderator' role.

      This specified user will be assigned the 'spam' role. Addding the spam role to a user will stop the
      user from posting new posts and comments. It doesn't delete any of the user's content, just
      prevents them from creating new content while having the spam role. Users are not notified of their spaminess
      in the UI, so if you want them to know about this, you must notify them