skip_example_on_ci and skip_example_on_runiverse check the environment for
variables called "CI" and "MY_UNIVERSE", respectively, and return TRUE
if it does not exist. Used to run examples if the package is being built
locally and there's a chance that vdat.exe exists. If the package is being built on
a continuous integration platform like GitHub Actions, the "CI" variable
will be TRUE and skip_example_on_ci will return FALSE. If it is being
built locally, "CI" will be "" and skip_example_on_ci will return
TRUE. Similarly, if the package is being built on R-Universe, the
"MY_UNIVERSE" variable will have your universe's name.