Checks and creates a directory recursively automatically.
Examples
dir <- file.path(tempdir(), "testdir")
dir.exists(dir)
#> [1] FALSE
dir <- initDir(dir)
dir.exists(dir)
#> [1] TRUE
print(dir)
#> [1] "/private/var/folders/l1/8y8sjzmn15v49jgrqglghcfr0000gn/T/RtmpUJIkTv/testdir"
unlink2(dir)