Ability to silence 7zip output

[arnaudh]

This is a minor feature request, but it would be nice to be able to silence the outputs of 7zip.

Currently seeing this when downloading/extracting a datadep:

7-Zip (a) [64] 16.02 : Copyright (c) 1999-2016 Igor Pavlov : 2016-05-21
--
p7zip Version 16.02 (locale=C,Utf16=off,HugeFiles=on,64 bits,4 CPUs Intel(R) Xeon(R) CPU E5-2686 v4 @ 2.30GHz (406F1),ASM,AES-NI)
Scanning the drive for archives:
1 file, 752601330 bytes (718 MiB)
Extracting archive: /root/.julia/datadeps/XXX/XXX.zip
--
Path = /root/.julia/datadeps/XXX/XXX.zip
Type = zip
Physical Size = 752601330
Everything is Ok
Folders: 2
Files: 48
Size:       9319283882
Compressed: 752601330

Seems like we could use the 7zip -bs switch like so: -bso0 -bsp0. This would disable standard output messages and progress information, while keeping error messages.

[oxinabox]

Making it configurable is annoying for everyone.
We should pick the right thing and do that always.
Is the right thing to always do -bso0 -bsp0?
I could easily be convinced of that.
PR would be appreciated

[arnaudh]

Is the right thing to always do -bso0 -bsp0?

I would say so. Knowing what compression software is used is an implementation detail of DataDeps, and as a user I only want to know if there was a failure (happy case should be silent, or perhaps a one-line statement e.g. "Datadep extracted to XXX").

I'll create a PR if you are convinced 🙂

[oxinabox]

Sounds good to me