Add Sink Implementation for Amazon S3 Bucket as a Schema Registry

Amazon S3 Bucket can be a schema registry, but there is no sink implemented.

Here are documents as references:

* [Schema Registry Sink](https://github.com/aliencube/AzureMessaging.SchemaRegistry/blob/dev/docs/schema-registry-sinks.md)
* [Schema Registry Sink for Azure Blob Storage](https://github.com/aliencube/AzureMessaging.SchemaRegistry/blob/dev/docs/schema-registry-sinks-blob.md)