Update coinc.xml interface definition
We should ensure that our uploaded coinc.xml file matches the interface definition required by EM follow-up at initial upload.
This schema is defined here: https://lscsoft.docs.ligo.org/ligo.skymap/interface.html.
Ideally, we should also verify that including any additional data or changing the order of our uploads does not significantly increase our latency.
This issue will be resolved when all related issues (#23 (closed), #24, #25 (closed), #87 ) are resolved.
Edited by Daniel Tang