Add ability to pull in initial information from AnVIL

[amstilp]

It might be helpful to pull in information from AnVIL and create a set of models when starting up, especially if you trash your devel database and want to start again. This would involve:

• Import any workspace owned by the service account
• Import any group where the service account is the admin
  • Import group-group memberships
  • Import group-account memberships (and related accounts)
• Import workspace sharing

Maybe there is more?

This could potentially be integrated with #13 which will audit the Django database against AnVIL.