Futurewarning in tiling method

```
/pylon5/mc3bggp/paraskev/SealsPytorch1/bin/iceberg_seals.tiling:17: FutureWarning: The value of this property will change in version 1.0. Please see https://github.com/mapbox/rasterio/issues/86 for details.
```

I suggest this warning gets tracked and make sure we update as soon as the used functionality changes.