Kuwait IBAN parsing rules

Examples

    iex>  %IbanEx.Iban{
    ...>    country_code: "KW",
    ...>    check_digits: "81",
    ...>    bank_code: "CBKU",
    ...>    branch_code: nil,
    ...>    national_check: nil,
    ...>    account_number: "0000000000001234560101"
    ...>  }
    ...>  |> IbanEx.Country.KW.to_string()
    "KW 81 CBKU 0000000000001234560101"