Always show job stats, even when in nirvana

When we enter nirvana there's no information displayed about the jobs,
which can make it ambiguous as to whether everything is green or if the
radiator isn't finding any jobs. This commit changes the hide/show logic
to hide the job table but leave the summary visible.
Merge pull request #24 from adrienthebo/nirvana-show-stats

Always show job stats, even when in nirvana