Add Commerce Scraper

- Some reports don't have IDs so we fallback to using a combination of the date and title
- [Some reports](http://www.oig.doc.gov/Pages/NOAA-Grantee-Sentenced-for-Misusing-Funds.aspx) don't have a pdf download. For these, I'm just setting that page as the report. Let me know if we should just skip these since they seem a bit more like announcements. [Some](http://www.oig.doc.gov/Pages/NIST-Grantee-Pleads-Guilty-to-Misuse-of-Federal-Funds.aspx) [other](http://www.oig.doc.gov/Pages/Former-Census-Contractor-Sentenced-for-Money-Laundering.aspx) [examples](http://www.oig.doc.gov/Pages/NOAA-Employee-Fired-for-Misuse-of-Purchase-Card.aspx).
- `urllib.parse` has some trouble finding the extension for some of these report urls. See the workaround [here](https://github.com/unitedstates/inspectors-general/commit/6a70ce115100066b615e53f40bdbf54e9ead9812#diff-39ad96d7559d7adf9c1c082619f3ac75R120).