message: Fix warnings in tests api_pool.
diff: @@ -32,7 +32,7 @@ fn sovrin_create_pool_ledger_can_be_called() {
  let pool_name = CString::new("test_open").unwrap();
  let pool_config = CString::new("{\"genesis_txn\": \"./test_open_src.txn\"}").unwrap();
  - std::fs::File::create("./test_open_src.txn");
  + std::fs::File::create("./test_open_src.txn").unwrap();
  let err = sovrin_create_pool_ledger_config(command_handle,
  pool_name.as_ptr(),
  @@ -42,8 +42,8 @@ fn sovrin_create_pool_ledger_can_be_called() {
  assert_eq!(ErrorCode::Success, err);
  let err = receiver.recv().unwrap();
  - std::fs::remove_file("./test_open_src.txn");
  - std::fs::remove_dir_all(EnvironmentUtils::pool_path("test_open"));
  + std::fs::remove_file("./test_open_src.txn").unwrap();
  + std::fs::remove_dir_all(EnvironmentUtils::pool_path("test_open")).unwrap();
  assert_eq!(ErrorCode::Success, err);
  }
  