Updated API from documentation release

Author: ct-sdks[bot]

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

@@ -4,7 +4,7 @@ type: Message
 displayName: ExpiredSession
 discriminatorValue: expired_session
 description: |
-  Generated when the session is expired.
+  Generated when the [Checkout Session](/installing-checkout#create-checkout-sessions) is expired.
 properties:
   code:
     type: string

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

@@ -0,0 +1,20 @@
+#%RAML 1.0 DataType
+(annotations.package): responses
+type: Message
+displayName: FailedToRefreshSession
+discriminatorValue: failed_to_refresh_session
+description: |
+  Generated when the [Checkout Session](/installing-checkout#create-checkout-sessions) fails to refresh.
+properties:
+  code:
+    type: string
+    description:
+  severity:
+    type: string
+    description: \`error`
+  message:
+    type: string
+    description: Failed to refresh session.
+  correlationId:
+    type: string
+    description: Unique identifier of the event.

api-specs/checkout/types/types.raml

@@ -13,6 +13,7 @@ CheckoutCompleted: !include responses/CheckoutCompleted.raml
 CheckoutLoaded: !include responses/CheckoutLoaded.raml
 CheckoutStarted: !include responses/CheckoutStarted.raml
 ExpiredSession: !include responses/ExpiredSession.raml
+FailedToRefreshSession: !include responses/FailedToRefreshSession.raml
 InitTimeout: !include responses/InitTimeout.raml
 InvalidLocale: !include responses/InvalidLocale.raml
 InvalidMode: !include responses/InvalidMode.raml