Add state & variables to GetExhangeResponse.

exchanges.yml

@@ -400,6 +400,21 @@ components:
           description: The steps completed by the exchange previously.
           items:
             type: string
+        state:
+          type: string
+          description: The status ("pending" | "complete" | "invalid") of the exchange, set to "pending" on creation.
+        variables:
+          type: array
+          description: Template variables to be used in the exchange.
+          items:
+            type: object
+            properties:
+              type:
+                type: string
+                description: The type of template.
+              template:
+                type: string
+                description: The template itself.
     WorkflowStep:
       type: object
       description: Object containing information about a workflow step.