Added first non SEPA countries

lib/iban_ex/country/gt.ex

@@ -0,0 +1,25 @@
+defmodule IbanEx.Country.GT do
+  @moduledoc """
+  Guatemala IBAN parsing rules
+
+  ## Examples
+
+  ```elixir
+      iex>  %IbanEx.Iban{
+      ...>    country_code: "GT",
+      ...>    check_digits: "82",
+      ...>    bank_code: "TRAJ",
+      ...>    branch_code: nil,
+      ...>    national_check: nil,
+      ...>    account_number: "01020000001210029690"
+      ...>  }
+      ...>  |> IbanEx.Country.GT.to_string()
+      "GT 82 TRAJ 01020000001210029690"
+  ```
+  """
+
+  @size 28
+  @rule ~r/^(?<bank_code>[A-Z]{4})(?<account_number>[0-9]{20})$/i
+
+  use IbanEx.Country.Template
+end