Upload circulars

• make ligo-followup-advocate pip installable
• add ligo-followup-advocate to setup.cfg
• create tasks.circulars.py to call the compose function to generate a circular, and also upload to gracedb
• edit tasks.dispatch to include circulars in the overall workflow, even for Burst triggers
• edit tasks.dispatch to create circular when EM Bright info is uploaded into gracedb for CBC triggers