title: Remove AKKA actor from actor system and create another actor with same path name
body: <p>I have Poll Event which has id, startDate, endDate, status and etc..
  startDate and endDate are future dates in long (milli seconds)
  value for status can be one of the Strings "active", "inactive" and "completed".</p>
  
  <p>when Poll object is saved in to database its status is "inactive". I wrote PollActor by extending UnTypedActor to change its status to "active" when startDate is reached, and to change its status to "completed" when endDate is passed. For unique name of the actor I have used id of the poll event. for example : <strong>"pollActor" + 12</strong>  where 12 is poll id. This is fine if I don't update the Poll event.
  Problem comes when I update the Poll. PollActor has the field final Poll poll. Once it is initialized I can't change its contents. So I want to remove existing PollActor on the poll and create a new PollActor when the Poll is Updated. I tried "Kill"ing and create new PollActor but it didn't work, thrown InvalidActorNameException.
  Please Suggest me what should I do in update case.</p>