Convert scrapers to use OpenCivicData tools and standard

Brought this up [on slack](https://civictechto.slack.com/archives/opencabinet/p1452553154000050).
- [**`opencivicdata/pupa`**](https://github.com/opencivicdata/pupa/), the scraper tool
- [**`opencivicdata/scrapers-ca`**](https://github.com/opencivicdata/scrapers-ca), the Canadian scraper repo
- [**Documentation**](http://docs.opencivicdata.org/en/latest/scrape/bills.html) on "Writing a Bill Scraper"
### Random Notes
- Thinking that we should ask the sunlight labs folks about creating a new bill `_type` (`order`?). Currently, [the docs say](http://docs.opencivicdata.org/en/latest/data/bill.html#basics) that only `bill` is a valid type, so not sure.
### To
- [ ] Discuss. Is this something we want to do?
- [ ] Create a 'ca/bill.py`scraper in 'opencivicdata/scrapers-ca`
- [ ] Migrate the `openorders` app to use the pupa database (which has a defined schema shared by all legislative scrapers and based on the spec)

cc: @jpmckinney