Add PyDAL support

From:

https://forums.couchbase.com/t/python-sdk-data-abstraction-layer-support/20389

"From my research, there are not many non-Mongo database abstraction options out there and pyDAL seems to be the most full-fledged solution available. As such, that would be the preference to interface with Couchbase. I’ve submitted a feature request to the project. 1

I recognise that the use of a database abstraction layer potentially reduces the ability to leverage the full functionality of Couchbase as opposed to using the Python SDK directly. In case where this is needed, use of the SDK directly would be employed.

Would the same disclaimer regarding support or approval apply to a project such as pyDAL? Would the Couchbase development team consider contributing to pyDAL to open up opportunity to allow developers using pyDAL the flexibility to switch from Mongo to Couchbase?"