cleanup

[bbolker]

(1) the package is failing on r-devel-windows-...-UCRT because lots of
packages are missing on that platform (rms, ggplot2, Hmisc, testthat)

(2) the noLD platform is listed under "additional issues"; when I look
at the logfile I see one place where a .Rout and a .Rout.save file are
off by a few least-significant digits, and one place in a test where an
additional warning is thrown during the testing process.