testURLs and read.testURLs have been removed, because it wasn’t clear that anyone was using them, and more modern tools are available from:
http://www.measurementlab.net/
Thanks to Iñaki Ucar, Adam H Sparks, and Roy Mendelssohn for their replies to a question posted to R-Devel helped me understand what I needed to do to fix problems identified in the CRAN Checks.