title: Stripe IOS SDK not matching AllResponseFields?
body: <p>I'm trying to do a simple count check for a customer to see if they need to add a source before moving onto another page. However, my calls to the STPCustomer object's attributes are not matching the information for the full response.  </p>
  
  <p>I've tried clearing the customer cache and reloading the customer, but uh... still no match.</p>
  
  <p>Here's a truncated like, essentials code.  The class has the STPPaymentContextDelegate attached.</p>
  
  <pre><code>private var customerContext = STPCustomerContext? 
  private var paymentContext = STPPaymentContext? 
  
  func setupStripe() {
  self.paymentContext = STPPaymentContext(customerContext: self.customerContext!)
  
      self.paymentContext?.hostViewController = self
      self.paymentContext?.delegate = self
  
      self.paymentView = STPPaymentMethodsViewController(configuration: STPPaymentConfiguration.shared(), theme: STPTheme.default(), customerContext: self.customerContext!, delegate: self)
  }
  
  func getCustomerSources() {
  
  if let customer = customerContext.retrieveCustomer({ (customer, error) in
          if customer != nil {
               print(customer.sources.count)
               print(customer.sources)
               print(customer.allResponseFields)
          }
      })
  }
  </code></pre>
  
  <p>When I run <code>getCustomerSources()</code> on the test customer, I am expecting:</p>
  
  <pre><code> 1
   [ba_1Dvf46LrBVaGM6Sq9qIYhOlJ]
   AnyHashable("id"): cus_number, AnyHashable("email"): rosa_diaz@gmail.com, AnyHashable("default_source"): ba_1Dvf46LrBVaGM6Sq9qIYhOlJ, AnyHashable("created"): 1548220659, AnyHashable("description"): LiG8WbVhT8SVhta8LdfUuWzOwQn2, AnyHashable("livemode"): 0, AnyHashable("object"): customer, AnyHashable("sources"): {
    data =     (
              {
          "bank_name" = "STRIPE TEST BANK";
          country = US;
          currency = usd;
          customer = "cus_EOQzwwGPjzopjS";
          fingerprint = 1AQMB9nzeGSGXHst;
          id = "ba_1Dvf46LrBVaGM6Sq9qIYhOlJ";
          last4 = 6789;
          metadata =             {
          };
          object = "bank_account";
          "routing_number" = 110000000;
          status = verified;
      }
     );
     "has_more" = 0;
     object = list;
     "total_count" = 1;
     url = "/v1/customers/cus_EOQzwwGPjzopjS/sources";
  }])
  </code></pre>
  
  <p>However, instead of my <code>1</code> and <code>ba_1Dvf46LrBVaGM6Sq9qIYhOlJ</code>, I am getting <code>0</code> and <code>[]</code>. <strong>But</strong> the <strong>allResponseFields</strong> section is the same. </p>
  
  <p>Any ideas as to why there's a discrepancy between what the STPCustomer object attributes are returning and what the actual response is telling me? </p>