Stacmap

What's Changed
* Add support for most `geopandas.explore` options (see [docs](https://stacmap.readthedocs.io/en/latest/tutorials/geopandas.html#Parameters) for details)
* Add optional matplotlib color parsing (12) by aazuspan in https://github.com/aazuspan/stacmap/pull/14

**Full Changelog**: https://github.com/aazuspan/stacmap/compare/0.0.3...v0.0.4

Bug fixes
- Layers don't disappear when an existing map is passed to `explore`

Features
- Implemented layer names to allow layer control for multiple collections

**Full Changelog**: https://github.com/aazuspan/stacmap/commits/0.0.3