Automatic scoring

Fixes #13 (closed) Fixes #14 (closed)

This splits off the scaling and recipe logic into a different module. This also fixes a bug related to scaling (#14 (closed)) and a bug related to hybrid pools (#13 (closed))

TODO before merge

• run scorers on sort?
• change digitalocean filters to be more generic (filter on region, tag, etc., should be a module)
• fix tests failing