Cartes

Consistency adjustments for conda-forge build

- switch to poetry for better dependency management
- atlas of maps
- bounds and projections for altair
- `.extent()` method patched to geodataframe
- leaflet methods on geo objects

**Full Changelog**: https://github.com/xoolive/cartes/compare/v0.6...v0.7

mostly fixes for recent versions of shapely
projections compatible with Altair

**Full Changelog**: https://github.com/xoolive/cartes/compare/v0.5...v0.6

More robust caching and typing

Bug fixes

Fix a redundant issue with HTTP error 504