R CMD check fails with dev roxygen2

[hadley]

  ══ Failed tests ════════════════════════════════════════════════════════════════
  ── Failure (test-document.R:49:3): documentation is built via document() ───────
  `document(file.path(tempdir(), "subsetCars"), lib = temp_libpath)` produced no output

Probably because roxygen2 now uses cli::cli_inform() and cli::cli_warn(). I'm aiming for a CRAN release May 13.