better formatting + error message in fetch matters task
changed matters database schema to reflect API
legistar_matters.rake updated to use the new magic

- We added some stuff in legistar.rb which hits an import.io API* that when given a Legistar documentation page URL will return the documented structure of the endpoint as JSON, and then that is printed in a way that is easy to include in the migrations files. 

*: https://import.io/data/set/?mode=loadSource&source=4c1ec1ba-762d-421d-9da0-a399be0919d0