Added geocoded_through

    class User < ActiveRecord::Base
      has_many :inventory_items
      geocoded_by :postal_code
      reverse_geocoded_by :latitude, :longitude
      after_validation :geocode
    end

    class InventoryItem < ActiveRecord::Base
      belongs_to :user
      geocoded_through :user
    end

irb(main):013:0> InventoryItem.near('M4J3J8').first.user.postal_code
=> "M4J3J8"
irb(main):014:0> InventoryItem.near('M4J3J8').first.reverse_geocode
=> "127-135 Dewhurst Blvd, East York, ON M4J 3J9, Canada"
irb(main):015:0>