Fix coding standards on tests

Author: n7studios

tests/ConvertKitAPITest.php

@@ -109,7 +109,10 @@ public function testGetSequenceSubscriptions()
         $this->assertIsArray($result['subscriptions']);
 
         // Assert sort order is ascending.
-        $this->assertGreaterThanOrEqual($result['subscriptions'][0]->created_at, $result['subscriptions'][1]->created_at);
+        $this->assertGreaterThanOrEqual(
+            $result['subscriptions'][0]->created_at,
+            $result['subscriptions'][1]->created_a
+        );
     }
 
     /**
@@ -134,7 +137,10 @@ public function testGetSequenceSubscriptionsWithDescSortOrder()
         $this->assertIsArray($result['subscriptions']);
 
         // Assert sort order.
-        $this->assertLessThanOrEqual($result['subscriptions'][0]->created_at, $result['subscriptions'][1]->created_at);
+        $this->assertLessThanOrEqual(
+            $result['subscriptions'][0]->created_at,
+            $result['subscriptions'][1]->created_a
+        );
     }
 
     /**