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

lib/iban_ex/country/hr.ex

@@ -1,6 +1,13 @@
 defmodule IbanEx.Country.HR do
   @moduledoc """
   Croatia IBAN parsing rules
+
+  ## Examples
+
+    iex> %IbanEx.Iban{country_code: "HR", check_digits: "12", bank_code: "1001005", branch_code: nil, national_check: nil, account_number: "1863000160"}
+    iex> |> IbanEx.Country.HR.to_string()
+    "HR 12 1001005 1863000160"
+
   """
 
   @size 21