Previously, if the arti process had died or been killed, we wouldn't
reach the point where we called "chutney stop".

If the user has CHUTNEY_PATH set, respect that value, rather than
cloning a local chutney.

Also, if we have a local chutney, then update it in case there have
been changes.

This makes sure that we're checking for a nonzero port in all cases.

Add MIT and Apache licenses

Closes #243

See merge request tpo/core/arti!152

Change sane_defaults() and with_directories()

See merge request tpo/core/arti!155

Also fix a couple of warnings introduced by now-unneeded imports
with new ed25519 crate.

This is part of the process for releasing our next version.

Also fix a couple of warnings introduced by now-unneeded imports
with new ed25519 crate.

This is part of the process for releasing our next version.

The sane_defaults() call is now the same as you get from a default
builder: by convention, we just call that method Default::default().

The with_directories() constructor makes more sense as a constructor
for the TorClientConfigBuilder than for TorClientConfig.

(Also fix a couple of typos)

UX improvements to with_coverage script

See merge request tpo/core/arti!143

This test seems unreliable on CI: we've got to disable them for now
so that we have a working CI system.  The CI failure is #238; the
ticket to repair them is #244.