title: basic firebase URL structure?
body: <p>I am building a very simple cron job backup system for a friend's firebase app; 
  I have PHP code, using firebase-php that can communicate with the firebase and the API docs state that adding the'?format=export" parameter will retrieve a .json file.  Cool, so far.</p>
  
  <p>My question is this: What path (after the firebase URL) is required? 
  The API doc appears to state that it should be /.json but it returns a 404 /json/ works on the simulator, but also returns a 404 in testing</p>
  
  <p>(note: looking for a single text file, similar to the "Export json" data dashboard, if possible)</p>
  
  <p>Thanks in advance.</p>