Pyfilesystem fix for AWS

pyfs expects AWS access/secret keys. This prevents it from working with VPC auth in prod. This removes the expectation. See: 

  https://github.com/pmitros/pyfs/commit/ca0ea11010def81a8fa1964e4a2b5f62f4f89d3e

This is tested on sandbox. 

Note that this also brings up pyfs to the latest version (not 0.4 as currently in prod). I am waiting on tests to run to see if this effects the system elsewhere.