.arcconfig

tests: flatten repo structure in test-commit.t

Let's move to parent directory before `hg init` repos, since they don't need to
be nested. It makes amend/strip messages that include full path to the backup
bundle shorter, for instance.

{
    "conduit_uri": "https://phab.mercurial-scm.org/api",
    "repository.callsign": "HG",
    "arc.land.onto.default": "@",
    "base": "hg:.^"
}