update changelog

Author: vincentsarago

CHANGELOG.md

@@ -38,6 +38,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Do not validates arbitrary dictionaries. Make `Type` a mandatory key for objects (https://github.com/developmentseed/geojson-pydantic/pull/94)
 - Add Geometry discriminator when parsing geometry objects (author @eseglem, https://github.com/developmentseed/geojson-pydantic/pull/101)
+- Mixed Dimensionality WKTs (make sure the coordinates are either all 2D or 3D) (author @eseglem, https://github.com/developmentseed/geojson-pydantic/pull/107)
 
 ### Removed