Fix/mktemp

[lassepe]

tempfile is not available on non-debian-based linux distributions. Thus, asdf-julia is currently broken on Arch Linux and most likely macos as well. This fixes things for Arch Linux. I cannot test on macos locally.

[dhanak]

Works on Debian

[lassepe]

@rkyleg could you review this one? Currently, asdf-julia is broken for non-debian users.

[lassepe]

@rkyleg do you know what is going on with the MacOS CI? It seemed like it was hanging. Now it is disabled completely.

[tdy]

Works for me locally on Arch. Would be great to get this merged upstream.

[lassepe]

There is something wrong with the MacOS tests still. They are running for more than an hour already and still haven't finished

[lassepe]

Unfortunately, there is no output or error message, it just hangs. So it's really hard to debug.

[FujishigeTemma]

@lassepe The tests fails because the --suffix option doesn't exist in macOS-builtin mktemp(https://www.mktemp.org/manual.html) and hangs at eval $cmd$page >> $releases. And it seemed that the .json suffix isn't always necessary, so I just turned it off and it works on my macOS.

releases=$(mktemp)
headers=$(mktemp)

[lassepe]

Thank you @FujishigeTemma, I pushed that to this branch as well.

@rkyleg woud you consider re-enabling the CI and, if it passes, merge this PR?