message: [key-manager] do not use is_ok in test
  When an is_ok fails, you are left knowing it is not ok. Then you have to
  change the test to unwrap the error. Then you know why it is not ok.
  TL;DR, is ok is not ok in  test ;)
  Closes:
  Approved by: joshlind
diff: @@ -407,12 +407,11 @@ fn test_ability_to_read_move_data() {
  }
  fn verify_ability_to_read_move_data<T: LibraInterface>(node: Node<T>) {
  - assert!(node.libra.last_reconfiguration().is_ok());
  - assert!(node.libra.retrieve_validator_set().is_ok());
  - assert!(node.libra.retrieve_validator_config(node.account).is_ok());
  - assert!(node.libra.retrieve_validator_set().is_ok());
  - assert!(node.libra.retrieve_validator_info(node.account).is_ok());
  - assert!(node.libra.retrieve_libra_block_resource().is_ok());
  + node.libra.last_reconfiguration().unwrap();
  + node.libra.retrieve_validator_set().unwrap();
  + node.libra.retrieve_validator_config(node.account).unwrap();
  + node.libra.retrieve_validator_info(node.account).unwrap();
  + node.libra.retrieve_libra_block_resource().unwrap();
  }
  #[test]
  @@ -491,8 +490,8 @@ fn test_key_manager_init_and_basic_rotation() {
  fn verify_init_and_basic_rotation<T: LibraInterface>(mut node: Node<T>) {
  // Verify correct initialization (on-chain and in storage)
  - assert!(node.key_manager.compare_storage_to_config().is_ok());
  - assert!(node.key_manager.compare_info_to_config().is_ok());
  + node.key_manager.compare_storage_to_config().unwrap();
  + node.key_manager.compare_info_to_config().unwrap();
  assert_eq!(node.time.now(), node.key_manager.last_rotation().unwrap());
  // No executions yet
  assert_eq!(0, node.key_manager.last_reconfiguration().unwrap());
  @@ -564,7 +563,7 @@ fn verify_execute<T: LibraInterface>(config: &NodeConfig, mut node: Node<T>) {
  // Verify a single execution iteration will perform the rotation and re-sync everything
  node.update_libra_timestamp();
  - assert!(node.key_manager.execute_once().is_ok());
  + node.key_manager.execute_once().unwrap();
  // Verify nothing to be done after rotation
  node.update_libra_timestamp();
  @@ -592,7 +591,7 @@ fn verify_execute<T: LibraInterface>(config: &NodeConfig, mut node: Node<T>) {
  // Verify that a single execution iteration will resubmit the transaction, which can then be
  // executed to re-sync everything up (on-chain).
  node.update_libra_timestamp();
  - assert!(node.key_manager.execute_once().is_ok());
  + node.key_manager.execute_once().unwrap();
  node.execute_and_commit(node.libra.take_all_transactions());
  assert_eq!(
  Action::NoAction,
  @@ -631,7 +630,7 @@ fn verify_execute_error<T: LibraInterface>(mut node: Node<T>) {
  // Perform each execution iteration a few times to see that everything is working
  for _ in 0..5 {
  node.update_libra_timestamp();
  - assert!(node.key_manager.execute_once().is_ok());
  + node.key_manager.execute_once().unwrap();
  }
  // Delete all keys in secure storage to emulate a failure (e.g., so that the key manager should
  