Disable the cache if debug=True.

Author: T4rk1n

dash/dash.py

@@ -760,4 +760,15 @@ def run_server(self,
                    port=8050,
                    debug=False,
                    **flask_run_options):
+
+        if debug:
+            # Disable the cache
+            # pylint: disable=unused-variable
+            @self.server.after_request
+            def after_req(rep):
+                rep.headers['Cache-Control'] = 'no-cache,' \
+                                               ' no-store,' \
+                                               ' must-revalidate'
+                return rep
+
         self.server.run(port=port, debug=debug, **flask_run_options)