Added all SEPA countries (IBANs from European Union countries) and minimal test coverage for countries

lib/iban_ex/country/ua.ex

@@ -1,10 +1,16 @@
 defmodule IbanEx.Country.UA do
   @moduledoc """
   Ukrainian IBAN parsing rules
+
+  ## Examples
+
+    iex> %IbanEx.Iban{country_code: "UA", check_digits: "21", bank_code: "322313", branch_code: nil, national_check: nil, account_number: "0000026007233566001"}
+    iex> |> IbanEx.Country.UA.to_string()
+    "UA 21 322313 0000026007233566001"
+
   """
 
   @size 29
   @rule ~r/^(?<bank_code>[0-9]{6})(?<account_number>[0-9A-Z]{19})$/i
-
   use IbanEx.Country.Template
 end