StructuredValue attributes support

With this release we added StructuredValue attribute type support and decoding these attributes to maps or structs.

v0.5.3 - Fix unsafe casting in entity attributes

This release add the pull request #9

It fixes the entity attributes retrieving, avoiding unsafe castings and panics.

v0.5.2

Added LastSuccessCode for SubscriptionNotification

v0.5.1 - Add support forr custom global headers in http requests

Merge pull request #6 from CDimonaco/feature/custom_headers_in_client…

v0.5.0

Added support for GeoJSON attributes.