Verify that a unified directory, API V2 is selected.

The first fail logic seems scoped to a single test file.

Set the flag globally.
Since the tests run in a container, cleanup is automagic.

Various test tweaks to allow for skipping tests & null strings.

From https://github.com/sstephenson/bats/issues/135 via @timkimber

The test harness will suppress output unless an error occurs.

Upgrade testing was failing in forked repos CI because the
source repo was hard-coded.  Use the CI environment to use
the fork's repo.

Use a regexp rather than a partial match to skip any DNS_CHECK_OPTIONS,
which in the current tests create whitespace, but could be anything.

Catch a missing inclusion of DNS_CHECK_OPTIONS for dig CNAME

Fixes #594 #272 #564