Account convenience methods improperly check arithmetic

[jmcph4]

Reproduction

let acct: Account = Account::new(1, "John Doe".to_string(), 0, HashMap::new());
let res: Result<(), AccountError> = acct.add_balance(1);
assert_eq!(res, Ok(()));

Actual Behaviour

Assert fails, as Account::add_balance returns AccountError::BalanceOutOfBounds.

Expected Behaviour

Assert succeeds, as Account::add_balance returns Ok(()).

Tasks

• Invert conditions in bounds checks for add_balance
• Invert conditions in bounds checks for add_holding

[jmcph4]

Closed by 02afee2.