Fix bug 1079932 - Add data

*This commit builds on #16.  Merge that first*

This pull request adds support for downloading and uploading web compat data using the API.  Most of the changes are in the tools/ folder:

- `resources.py` - Hold API data, serialize / deserialize from JSON API, compare collections of resources
- `load_spec_data.py` and `load_webcompat_data.py` - Converted to use resources, and to use sync paradigm rather than loading to an empty API.
- `download_data.py` - Download API data as JSON API to a folder
- `upload_data.py` - Upload API data from a folder

A separate repo contains a starting data set of browser, version, feature, maturity, and specification data:

https://github.com/jwhitlock/browsercompat-data

This data is loading in a fresh API:

http://browsercompat.herokuapp.com

These changes and repos enable a github-based workflow:

1. Fork and branch `browsercompat-data`
2. Import into a local copy of web-platform-compat using `upload_data.py`
3. Make some changes in the local copy
4. Export changes using `download_data.py`
5. Push changes to `browsercompat-data` fork, submit a pull request

Once there is a web-based editing interface, a periodic script or edit hook could ensure `browsercompat-data` is kept in sync with the API.
Yes, both are still up.

http://doesitwork-dev.allizom.org is an import of the webcompat.org scraped data and some KumaScript data.  webcompat.org stopped importing data and improving the scraper, so it's unclear if this is a good starting point or a dead end yet.

http://browsercompat.herokuapp.com has the same data, minus supports and some data Jeremie P. and I have agreed is bad.  The idea is that known good data can be the basis for sanity checks of automated imports.  If the import matches the good data, then accept the import.  If it doesn't match, then flag for a human to diagnose.  The data is stored in a separate repo:

https://github.com/jwhitlock/browsercompat-data