feat: added activities to schema validation

Author: theburningmonk

lib/index.js

@@ -147,6 +147,7 @@ class ServerlessStepFunctions {
         stateMachines: { type: 'object' },
         validate: { type: 'boolean' },
         noOutput: { type: 'boolean' },
+        activities: { type: 'array' },
       },
       required: ['stateMachines'],
     };