Fix weird test error

test/checkouts_test.rb

@@ -55,7 +55,8 @@ class CheckoutsTest < Test::Unit::TestCase
     checkout = ShopifyAPI::Checkout.find(@expected_checkout_id)
 
     fake "checkouts/#{@expected_checkout_id}/payments", method: :get, status: 202, body: load_fixture('payments')
-    assert_equal 10.00, checkout.payments.first.amount
+
+    assert_equal 10.00, checkout.payments.first.attributes['amount']
   end
 
   test ":shipping_rates returns shipping rates for a checkout" do

test/fixtures/payment.json

@@ -1,5 +1,6 @@
 {
   "payment" : {
+    "id": "east-44a400ef20b36e38f10b882cb7260796",
     "amount": 10.00,
     "session_id": "east-44a400ef20b36e38f10b882cb7260796",
     "unique_token": "my-client-generated-idempotency-token"

test/fixtures/payments.json

@@ -1,9 +1,10 @@
-[
-  {
-    "payment" : {
+{
+  "payments" : [
+    {
+      "id": "east-44a400ef20b36e38f10b882cb7260796",
       "amount": 10.00,
       "session_id": "east-44a400ef20b36e38f10b882cb7260796",
       "unique_token": "my-client-generated-idempotency-token"
     }
-  }
-]
+  ]
+}