Upgrade gephysio to auxiliary reaper

[gsfr]

An auxiliary reaper is one that cannot make a reap/sort decision on its own, but relies on another reaper's state file for additional information. This allows for decoupling and order independence. Once the primary reaper has successfully reaped a desired item, the aux reaper can send its matching data accordingly.

Depends on #45.

Needed bug fix: incorrect usage of util.create_archive() (metadata and outdir arguments are swapped). Thanks @ambrussimon-invenshure.
https://github.com/scitran/reaper/blob/master/reaper/gephysio.py#L62