crop creator is optional

doesn't get set when crop has just been requested

app/models/crop.rb

@@ -16,7 +16,7 @@ class Crop < ApplicationRecord
   has_many :seeds
   has_many :harvests
   has_many :plant_parts, -> { distinct.reorder("plant_parts.name") }, through: :harvests
-  belongs_to :creator, class_name: 'Member'
+  belongs_to :creator, class_name: 'Member', optional: true
   belongs_to :requester, class_name: 'Member', optional: true
   belongs_to :parent, class_name: 'Crop', optional: true
   has_many :varieties, class_name: 'Crop', foreign_key: 'parent_id'