title: Accessing the state from within a redux-observable epic
body: <p>I am using redux to build a little fusball-manager. Basically it's a page that shows the score of both teams and some buttons to increment them. I have actions like <code>{ type:"GOAL_UP", team:"red" }</code> for which the reducer will change the corresponding value (score) in the state.</p>
  
  <p>Now I want to add an epic that whenever it encounters a <code>GOAL_UP</code> checks if one of the two teams has won the game. If a team has reached a score of 8, I want it to dispatch a <code>GAME_WON</code> action. My problem is that I have to access the state to know the score of each team. I cannot find a way to access the state from within an epic.</p>
  
  <p>Is accessing the state out of scope for redux-observable? If so, how would you solve this problem?</p>
  
  <p>I am thinking about having the new score as a property in the <code>GOAL_UP</code> action. Something like this <code>{ type:"GOAL_UP", team:"red", newScore:8 }</code>. But somehow this feels wrong. I also have two physical buttons on the fusball-table that are connected with web sockets, which dispatch the <code>GOAL_UP</code> action. Since they are not triggered from my ui they don't know about the state.</p>
  
  <p>I could also think of dispatching the <code>GAME_WON</code> action in the render function of my ui component if the score of either team is 8. But that feels even more wrong :)</p>
  
  <p>Input is very welcome, Thanks</p>