Events: Look at all endpoints

[reginafcompton]

The events scraper should hit all related endpoints, e.g., event agenda items - that is, if an event agenda item changes, but the event does not change, then the scraper should catch the change.

[fgregg]

I investigated this a little tonight, and the issue is that attachment are nowhere in the API. So, we have no way of using the API to figure out which events had updated attachments.

Given that, I adjusted legistar-scraper and the lametro and chicago scrapers to scrape all events every hour.