Add a developer mode via --dev argument

Closes #69 (closed)

arkindex_worker/worker/__init__.py

@@ -86,6 +86,8 @@ class ElementsWorker(
 
     @property
     def store_activity(self):
+        if self.args.dev:
+            return False
         assert (
             self.process_information
         ), "Worker must be configured to access its process activity state"