Add tests for LV navigation in handle_info

[idabmat]

I haven't dug too deep into #209 but I wanted to contribute some failing tests to exhibit the behaviour. I hope this helps clarify the issue. Or am I holding phoenix_test wrong?

It might also be worth adding that an equivalent LV test works:

test "click link", %{conn: conn} do
  {:ok, view, _} = live(conn, "/live/handle_info")

  view
  |> element("a", "Redirect")
  |> render_click()

  assert_redirect(view, "/live/index")
end