Add more examples for Integer.parse

- show behavior of parsing with unparsable suffix bits
- show behavior of parsing float as integer

test/koans/numbers_koans_test.exs

@@ -11,6 +11,8 @@ defmodule NumbersTests do
       '7',
       "1234",
       42,
+      " years",
+      {:multiple, [1, ".2"]},
       34.5,
       1.5,
       35.0,