updated for Crystal 0.35.1

[vectorselector]

Hello, I updated this shard for Crystal 0.35.1
Basically, the JSON.mapping is out, and it's now just extending each class with JSON::Serializable

I added one more method for creating a document with a custom (out of band) ID, which I need for my work:

    def create_document_custom_id(database, object, id) : Response::DocumentStatus
      Response::DocumentStatus.from_json(
        put(URL::DOC % {database, id}, body: object.to_json)
      )
    end 

I confess to not having added a unit test for this method, which I will do at some point.