propagation of STAREs #105

until SpatioTemporal/STARE#105 is resolved, we should add logic to 
- cover_from_ring(lat, lon, level)
- cover_from_hull(lat, lon, level)

```python
s_range = pystare.to_compressed_range(sids)
expanded = pystare.expand_intervals(s_range, -1, multi_resolution=True)
```

Note that pystare.to_compressed_range(sids) is very slow. Lookups will be significantly more costly.