Updated API from documentation release

Author: ct-sdks[bot]

api-specs/checkout/types/responses/ResponseMessage.raml

@@ -7,10 +7,6 @@ examples:
   info Message: !include ../../examples/message/InfoOrderCreatedMessage.json
   error Message: !include ../../examples/message/ErrorInitBadConfigMessage.json
 properties:
-  payload:
-    description: |
-      Additional data about the event.
-    type: object
   correlationId:
     description: |
       Unique identifier of the event.

api-specs/checkout/types/transactions/TransactionItem.raml

@@ -2,10 +2,13 @@
 (annotations.package): Transaction
 (annotations.beta): true
 displayName: TransactionItem
-type: TransactionItemDraft
+type: object
 description: |
   Payment information related to the [Transaction](/transactions-api#transaction).
 properties:
+  amount?:
+    type: Amount
+    description: Money value of the Transaction Item.
   payment?:
     type: PaymentReference
     description: Reference to the [Payment](/../api/projects/payments#payment) associated with the Transaction Item.