message: Add timeout for receiving in integration tests.
diff: @@ -16,6 +16,8 @@ use std::fs;
  use std::ptr::null;
  +use std::time::Duration;
  +
  use utils::callbacks::CallbacksHelpers;
  use std::sync::mpsc::{channel};
  @@ -43,7 +45,7 @@ fn sovrin_create_pool_ledger_can_be_called() {
  assert_eq!(ErrorCode::Success, err);
  - let err = receiver.recv().unwrap();
  + let err = receiver.recv_timeout(Duration::from_secs(1)).unwrap();
  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);
  @@ -77,7 +79,7 @@ fn sovrin_open_pool_ledger_can_be_called() {
  callback);
  assert_eq!(ErrorCode::Success, err);
  - let err = receiver.recv().unwrap();
  + let err = receiver.recv_timeout(Duration::from_secs(1)).unwrap();
  assert_eq!(ErrorCode::Success, err);
  //TODO separate test to check error after open the same pool multiply times
  @@ -88,6 +90,6 @@ fn sovrin_open_pool_ledger_can_be_called() {
  callback);
  assert_eq!(ErrorCode::Success, err);
  - let err = receiver.recv().unwrap();
  + let err = receiver.recv_timeout(Duration::from_secs(1)).unwrap();
  assert_eq!(ErrorCode::PoolLedgerInvalidPoolHandle, err);
  }
  