RUSTSEC-2020-0168: mach is unmaintained

[github-actions[bot]]

mach is unmaintained

Details
Status	unmaintained
Package	mach
Version	0.3.2
URL	https://github.com/fitzgen/mach/issues/63
Date	2020-07-14

Last release was almost 4 years ago.

Maintainer(s) seem to be completely unreachable.

Possible Alternative(s)

These may or may not be suitable alternatives and have not been vetted in any way;

• mach2 - direct fork

See advisory page for additional details.

[Dentosal]

Fix merged upstream here, just waiting for the update to propagate.