update for 1.0.0rc2 in which Record.record?/2 was removed

Record.record?/1 and /2 were removed in Elixir 1.0.0rc2. I added a private method with relevant functionality from the deprecated function.

Original Record.record?/2 for reference:
````elixir
@doc false
defmacro record?(data, kind) do
  case Macro.Env.in_guard?(__CALLER__) do
    true ->
      quote do
        is_tuple(unquote(data)) and tuple_size(unquote(data)) > 0
          and :erlang.element(1, unquote(data)) == unquote(kind)
      end
    false ->
      quote do
        result = unquote(data)
        is_tuple(result) and tuple_size(result) > 0
          and :erlang.element(1, result) == unquote(kind)
      end
  end
end
````