rusterize 0.4.0

This version introduces two main new features:

1. Datatype runtime polymorphism: a custom datatype can be selected for the output raster to save some memory space
2. GeometryCollection support: now (multi)polygon and (multi)linestring geometries can be rasterized even within nested GeometryCollection types without exploding the geometries before processing

In addition, a new function parameter burn has been introduced to rasterize a custom value when field is not specified.

What's Changed

• New feats: Datatype polymorphism and GeometryCollection support by @ttrotto in #8

Full Changelog: v0.2.0...v0.4.0