Support migrating data from ADLS Gen2 to Pachyderm

[albscui]

We want to support Azure customers who use ADSL Gen2.

As a first pass, we can use Pachyderm pipelines to ingest data from ADLS Gen2. The pipeline would be a cron pipeline that runs on a cadence, and has authority to access ADLS Gen2.

After this is implemented, we can work on a more sophisticated variant described here #41