Add multi_output config value (Always true).

Author: T4rk1n

dash/dash.py

@@ -321,6 +321,7 @@ def serve_layout(self):
 
     def _config(self):
         config = {
+            'multi_output': True,
             'url_base_pathname': self.url_base_pathname,
             'requests_pathname_prefix': self.config['requests_pathname_prefix']
         }
@@ -935,7 +936,9 @@ def add_context(*args, **kwargs):
                 else:
                     response = {
                         'response': {
-                            output.component_property: output_value
+                            'props': {
+                                output.component_property: output_value
+                            }
                         }
                     }