burn doesn't handle antimeridian crossings

[jaybo]

Given a polygon which crosses the antimeridian, burn returns the wrong tileset.

at zoom=3, burn returns the following instead of the correct set of 4 tiles:

array([[0, 4, 3],
       [1, 4, 3],
       [2, 4, 3],
       [3, 4, 3],
       [4, 4, 3],
       [5, 4, 3],
       [6, 4, 3],
       [7, 4, 3],
       [0, 5, 3],
       [1, 5, 3],
       [2, 5, 3],
       [3, 5, 3],
       [4, 5, 3],
       [5, 5, 3],
       [6, 5, 3],
       [7, 5, 3]], dtype=int64)

I think the fundamental problem is that find_extrema() just does a min/max operation which ignores the crossing.

rename to antimeridian.geojson: antimeridian.txt