WIP: Create initial circular from VOEvent, not GraceDb

This makes it easy to generate sample circulars from the notices
in the User Guide.

Still to do:

* Port remaining circular types.
* Add support for multiple VOEvents so that our update circulars
  can describe the history of the event (including, but not limited
  to, changes to the localization).
3 jobs for notice-from-voevent in 2 minutes and 49 seconds (queued for 1 second)
latest
Status Name Job ID Coverage
  Build
passed build #281552

00:00:17

 
  Test
passed lint #281554

00:00:21

failed test #281553

00:02:31

69.0%
 
Name Stage Failure
failed
test Test
usage: setup.py compose [-h] [-m]
['A. Einstein IAS)' ['A. Einstein (IAS' ...]]
VOEVENT.xml
setup.py compose: error: argument VOEVENT.xml: can't open 'S1234': [Errno 2] No such file or directory: 'S1234'
usage: setup.py compose [-h] [-m]
['A. Einstein IAS)' ['A. Einstein (IAS' ...]]
VOEVENT.xml
setup.py compose: error: argument VOEVENT.xml: can't open 'S2468': [Errno 2] No such file or directory: 'S2468'
ERROR: Job failed: exit code 1