Remove manual promotion code test (#1931)

* removed manually maintained promotion code test (will be convered by generated example tests)

* regenerated GeneratedExamplesTest

Author: jar-stripe

tests/Stripe/GeneratedExamplesTest.php

@@ -2415,6 +2415,18 @@ public function testPromotionCodesGet2()
     }
 
     public function testPromotionCodesPost()
+    {
+        $this->expectsRequest('post', '/v1/promotion_codes');
+        $result = $this->client->promotionCodes->create([
+            'promotion' => [
+                'type' => 'coupon',
+                'coupon' => 'Z4OV52SU',
+            ],
+        ]);
+        self::assertInstanceOf(PromotionCode::class, $result);
+    }
+
+    public function testPromotionCodesPost2()
     {
         $this->expectsRequest(
             'post',