San Marino IBAN parsing rules

Examples

    iex>  %IbanEx.Iban{
    ...>    country_code: "SM",
    ...>    check_digits: "86",
    ...>    bank_code: "03225",
    ...>    branch_code: "09800",
    ...>    national_check: "U",
    ...>    account_number: "000000270100"
    ...>  }
    ...>  |> IbanEx.Country.SM.to_string()
    "SM 86 U 03225 09800 000000270100"