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* ``register_view`` decorator (instead of __view_name__ document property) to use CouchBase views easier
* EmailField.is_valid(email) is implemented and does work
* ViewSync.download() now downloads within their bucket folder and supports spatial views too
* ViewSync.upload() is implemented and does work
* CustomField abstract class can hold any type of value including dictionary
* doc.delete() method that is equal to doc.bucket.delete(doc.doc_id, doc.cas_value)
* Removed CredentialsNotSetError and using RuntimeError instead on connection
* Fixed dependency errors on installation