Russia IBAN parsing rules

Examples

    iex>  %IbanEx.Iban{
    ...>    country_code: "RU",
    ...>    check_digits: "03",
    ...>    bank_code: "044525225",
    ...>    branch_code: "40817",
    ...>    national_check: nil,
    ...>    account_number: "810538091310419"
    ...>  }
    ...>  |> IbanEx.Country.RU.to_string()
    "RU 03 044525225 40817 810538091310419"