Fix flow typing

index.js.flow

@@ -98,27 +98,27 @@ declare type PaymentDiscount = {
   /**
    * A string used to uniquely identify a discount offer for a product.
    */
-  identifier: string
+  identifier: string,
 
   /**
    * A string that identifies the key used to generate the signature.
    */
-  keyIdentifier: string
+  keyIdentifier: string,
 
   /**
    * A universally unique ID (UUID) value that you define.
    */
-  nonce: string
+  nonce: string,
 
   /**
    * A UTF-8 string representing the properties of a specific discount offer, cryptographically signed.
    */
-  signature: string
+  signature: string,
 
   /**
    * The date and time of the signature's creation in milliseconds, formatted in Unix epoch time.
    */
-  timestamp: number
+  timestamp: number,
 }