Batch upsert method for Airtable class

[lkesich]

Detailed Description

It would help me if there was a Parsons method in the Airtable class that creates a performUpsert request. For my purposes, it's important to be able to supply arguments to the fieldsToMergeOn array. This would reduce the number of calls needed to achieve the same effect with existing update_record and insert_record methods.

Priority

This is a low priority for me--I will use it when it's complete, but in the meantime I'll use another Python wrapper for the airtable API.

[matthewkrausse]

I can work on this.

[lkesich]

Thank you! The batch_upsert method from pyAirtable is exactly what I'm looking for.