replace Presenter#invoice_date with a delagator

app/models/invoice/data_presenter.rb

@@ -4,8 +4,8 @@ class Invoice
   class DataPresenter
     attr_reader :invoice
 
-    delegate :data, :date, to: :invoice
-    delegate :number, to: :invoice, prefix: true
+    delegate :data, to: :invoice
+    delegate :number, :date, to: :invoice, prefix: true
 
     FINALIZED_NON_SUCCESSFUL_STATES = %w(canceled returned).freeze
 
@@ -83,10 +83,6 @@ class Invoice
       all_eligible_adjustments.select { |a| a.originator_type == 'Spree::TaxRate' }
     end
 
-    def invoice_date
-      date
-    end
-
     def paid?
       data[:payment_state] == 'paid' || data[:payment_state] == 'credit_owed'
     end

spec/system/admin/orders/invoices_spec.rb

@@ -31,6 +31,7 @@ describe '
     login_as_admin
     visit spree.edit_admin_order_path(order)
   end
+
   describe 'creating invoices' do
     context 'when the order has no invoices' do
       it 'creates an invoice for the order' do