Newapi

Per @johnmyleswhite, I'm submitting this (pretty massive) update to GeoIP. I've simplified a bunch of things, and most significantly, it will auto-update based on MaxMind v2 data. Please see the README and the tests for example usage.

I've deprecated the existing exposed functions (hopefully correctly).


Not sure I'm a fan of having the auto-update rolled into the `geolocate` function call. Yes, it ensures you're using the newest files from MaxMind, but for production uses, I wouldn't want an update unexpectedly occurring.

Feels like we should be explicit in the documentation about calling the `update` function, so that users update as they feel in the same way users run `Pkg.update()` as they desire.