Separate Archimedes as an Etna service

[graft]

Currently, Timur runs "manifest" scripts and returns consignments using a /consignment endpoint. This endpoint already neatly encapsulates all of the manifest functionality - it accepts a script argument as a text block, parses it and runs through the code, making the necessary calls to Magma, Rtemis or Pythia as appropriate.

This functionality should be separated into its own service (Archimedes), which would provide a standalone manifest-crunching service separate from Timur. This would have a few advantages:

1. Other services can store manifest script blocks and run them via Archimedes without having to interact with Timur
2. Archimedes can expand to deal with its own concerns (e.g., running delayed jobs, caching, etc.) without interfering with Timur development.

There is a modicum of coupling involved - mostly in the form of script code obsolescence and syntax highlighting - but this coupling isn't much worse than the current situation.

To make this change we:

1. Copy the repo to mountetna/archimedes
2. Delete code not relating to archimedes (essentially, everything not in lib/models/archimedes and the endpoint line in server.rb
3. Create a deploy process for archimedes (putting Rtemis and Pythia on the same machine)
4. Delete archimedes code from Timur.