Function for downloading & testing url/internet connection according to CRAN policy
Example solution strongly based on https://community.rstudio.com/t/internet-resources-should-fail-gracefully/49199/12
as suggested by kvasilopoulos
Usage
test_url(link, output, quiet = FALSE)
Arguments
link
character vector with URL to check
output
character vector for output file name
quiet
logical vector (TRUE or FALSE) to be passed to curl_download function. FALSE by default