Skipping on CRAN is fine because of the file downloads, but why skip these tests on Travis/appveyor? If tests fail when the required unrar programs aren’t installed then this should be handled gracefully — check for presence of the unrar utility and report back to the user if not installed.
Because unrar utils aren’t standard we need to add this info to Additional requirements on DESCRIPTION.
…ng locally sometimes
…lure if .rar is corrupted