Merge pull request #451 from nnc/po_updated_date

Fix PurchaseOrder#updated_date_utc

Author: CloCkWeRX

lib/xeroizer/models/purchase_order.rb

@@ -32,13 +32,13 @@ class PurchaseOrder < Base
       string  :type
       decimal  :currency_rate
       string  :currency_code
-      guid  :branding_theme_id 
+      guid    :branding_theme_id 
       string  :status 
       string  :line_amount_types
       decimal  :sub_total
       decimal  :total_tax
       decimal  :total 
-      date    :updated_date_UTC
+      datetime_utc :updated_date_utc, :api_name => 'UpdatedDateUTC'
       boolean :has_attachments
 
       has_many     :line_items