Adapt some tests for OpenBSD:
- scrollback_spec:
- seq(1) is not available on OpenBSD: we'd use jot(1).
- Instead use a (hopefully) portable awk(1) snippet.
- channels_spec
- job_spec
- tui_spec
The test.functional.helpers and test.unit.helpers modules now include
all of the public functions from test.helpers, so there is no need to
separately require('test.helpers').