XIVAPI backend

[karashiiro]

Is your feature request related to a problem? Please describe.
Waiting on updates for bingode is not ideal.

Describe the solution you'd like
An XIVAPI backend, so that no library updates need to happen to keep software functional.

[karashiiro]

Created blank project at https://github.com/xivapi/godexivapi

[karashiiro]

Oh, I probably want to do this after #7 so that all future provider development can be done on a clean foundation.

[karashiiro]

Will remake this in this repo, under a pkg subdirectory.

[karashiiro]

Putting this on hold, I need a decent way of dealing with XIVAPI's rate limit, it's really not suited to massive numbers of lookups.