message: Resolve fixme for restoring merkle tree for pool.
diff: @@ -47,7 +47,10 @@ struct PoolWorker {
  impl PoolWorker {
  fn restore_merkle_tree(&mut self) {
  - let f = fs::File::open("pool_transactions_sandbox").expect("open file"); //FIXME use file for the pool
  + let mut p = EnvironmentUtils::pool_path(self.name.as_str());
  + p.push(&self.name);
  + p.set_extension("txn");
  + let f = fs::File::open(p).expect("open file");
  let reader = io::BufReader::new(&f);
  for line in reader.lines() {
  let line: String = line.expect("read transaction line");
  