Update required Stripe API version to 2019-09-09

CRM/Core/Payment/Stripe.php

@@ -16,7 +16,7 @@ class CRM_Core_Payment_Stripe extends CRM_Core_Payment {
    *
    * @var string
    */
-  const API_VERSION = '2019-08-14';
+  const API_VERSION = '2019-09-09';
 
   /**
    * Mode of operation: live or test.

docs/index.md

@@ -12,7 +12,7 @@ View this extension in the [Extension Directory](https://civicrm.org/extensions/
 * PHP 7.1+
 * Jquery 1.10 (Use jquery_update module on Drupal).
 * Drupal 7 / Joomla / Wordpress (latest supported release). *Not currently tested with other CMS but it may work.*
-* Stripe API version: 2019-08-14
+* Stripe API version: 2019-09-09
 * Drupal webform_civicrm 7.x-4.22+ (if using webform integration)
 
 If using test mode with drupal webform_civicrm you need this patch: https://github.com/colemanw/webform_civicrm/pull/266

docs/release/release_notes.md

@@ -21,7 +21,7 @@
 
 * Use Stripe Elements: https://stripe.com/payments/elements.
 * Use PaymentIntents and comply with the European SCA directive (https://stripe.com/docs/strong-customer-authentication).
-* Require Stripe API Version: 2019-08-14 and ensure that all codepaths specify the API version.
+* Require Stripe API Version: 2019-09-09 and ensure that all codepaths specify the API version.
 * Switch publishable key/secret key in settings (upgrader does this automatically) so they are now "correct" per CiviCRM settings pages.
 * Support cards using 3dsecure and cards not using 3dsecure (workflows with Stripe are slightly different but both are now handled).