CRAN check issues

[Robinlovelace]

Message from CRAN:

Please see the problems shown on
https://cran.r-project.org/web/checks/check_results_stats19.html.

Please correct before 2021-03-14 to safely retain your package on CRAN.

It seems we need to remind you of the CRAN policy:

'Packages which use Internet resources should fail gracefully with an informative message
if the resource is not available or has changed (and not give a check warning nor error).'

This needs correction whether or not the resource recovers.