Add option to qinfo to print task IDs

[UplandsDynamic]

Adding the option to qinfo to print IDs (PIDs) of running clusters provides an easy way for scripts and process managers to fetch their PID(s).

[codecov-io]

Current coverage is 90.59%

Merging #173 into master will decrease coverage by 6.02%

1. 3 files (not in diff) in django_q/brokers were modified. more
   • Misses +82
   • Hits -82
2. 1 files (not in diff) in django_q were modified. more
   • Misses +76
   • Hits -76

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[Koed00]

I like the idea , it's simple enough.
Unfortunately I just deprecated optparse for argparse, to be compatible with Django 1.9 and 1.10.
Do you mind changing that?

I'll add a test when you're done.

[UplandsDynamic]

Thanks! I added this option as a convenient way to reference the PIDs of running clusters from the management scripts I've written to run django_q as a service on FreeBSD. The scripts create a pid file when a cluster starts, then use the --ids option to easily check for running clusters when stopping/restarting the service. Works like a charm.

I've committed the change from optparse to argparse.

[UplandsDynamic]

Is this still on track to be merged for inclusion in the next release?
Thanks.

[Koed00]

Sure. Thanks for reminding me. I'll merge it to master when I can.
The release itself will have to wait till the weekend.