A Shiny App that inspects the DESCRIPTION file of a package,
finds all of the dependencies, and lists the R version required (Depended on)
by each of those packages. This should help help you figure out what the minimum version
of R your package should depend on.
It can be found online here: https://ateucher.shinyapps.io/check_r_versions_of_package_dependencies/
This was inspired by this twitter thread and the subsequent realization that I was not being very careful about this in my own packages.