The io/ioutil package has been deprecated in Go 1.16. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
It is not directly related to signal-handling, so can well live
in its own package.
Also added a variant that doesn't take a directory to write files
to, for easier consumption / better match to how it's used.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>