Make sure the action status is correctly set

fixes #719

Author: cderici

juju/action.py

@@ -6,13 +6,16 @@ class Action(model.ModelEntity):
     def __init__(self, entity_id, model, history_index=-1, connected=True):
         super().__init__(entity_id, model, history_index, connected)
         self.results = {}
+        self._status = self.data['status']
 
     @property
     def status(self):
-        return self.data['status']
+        return self._status
 
     async def fetch_output(self):
-        self.results = await self.model.get_action_output(self.id)
+        completed_action = await self.model._get_completed_action(self.id)
+        self.results = completed_action.output
+        self._status = completed_action.status
 
     async def wait(self):
         self.results or await self.fetch_output()