example.ini: disable all optional keys, to be sure the user won't use them if not needed

3 jobs for <span class="ref-name">v2.1-acme-draft-16</span> in 10 minutes and 3 seconds (queued for 21 seconds)
Status Job ID Name Coverage
  Test
passed #471
jessie

00:03:43

88.0%
passed #472
jessie_backport

00:03:12

88.0%
passed #473
stretch

00:03:06

88.0%