Restic returns 3 when some of the files it found disappeared while
taking the backup. This is normal since we're not actually taking
static filesystem snapshots, and the restic backup is still properly
created, so we can just ignore it.

Switch default compression to zstd

Closes #10

See merge request !28

The 'zstd' tool will also happily decompress lz4-encoded streams,
solving the backwards compatibility problem.

Update module github.com/golang-migrate/migrate/v4 to v4.15.1

See merge request !24

Use --repository-file to avoid leaking passwords in logs

Closes #3

See merge request !23

This issue prevents "restic init" from understanding the
--repository-file option in restic versions prior to 0.12, so we just
pass the --repo option as is in that case.

Also fixes handling of exclude / exclude_files options.

Fixes issue #3.

Allows Gitlab to gather MR metrics on test coverage and other
issues. Tests are anyway run again by dpkg-build.

Update module github.com/mattn/go-sqlite3 to v1.14.9

See merge request !25

See https://github.com/mattn/go-sqlite3/issues/209 for reference.

Reuse a pool of cache directories

Closes #6

See merge request !22

Update module github.com/golang-migrate/migrate/v4 to v4.15.0

See merge request !21

Update module github.com/mattn/go-sqlite3 to v1.14.8

See merge request !17

Fix some issues reported by lintian

See merge request !20

This should make tabacco use a lot less disk space in /var/cache,
fixing issue #6.

Changes-By: lintian-brush
Fixes: lintian: package-uses-old-debhelper-compat-version
See-also: https://lintian.debian.org/tags/package-uses-old-debhelper-compat-version.html

Command execution logic moves from the Handler type to Repository, to
allow us to introduce Repository-owned command-scoped contexts later.