Upgrade specs2 and remove SignificantFigures
use the latest specs2 version (2.4.8)
Merge pull request #360 from ambiata/topic/specs2-upgrade-significant-figures

Upgrade specs2 and remove SignificantFigures
Add Chord windowing reducer logic and tests

This isn't currently wired up, and requires squash to be completed first.
Always write out the last fact before each chord entity window (for state-based features)
Merge pull request #359 from ambiata/topic/chord-windowing-part-1

Add Chord windowing reducer logic and tests
Updating notion and poacher versions
Merge pull request #362 from ambiata/topic/mr

Updating notion and poacher versions
Added argonaut to the list of dependencies for the projects and the storage sub-project in particular
Added agronaut dependency to core and data
Added CodecJson instance for Identifier
CodecJson instance for Date
Added CodecJson instance for SnapshotId
WIP: SnapshotMeta
Proper CodecJson instance for Date
Cleaned up the CodecJson instance for Date
CodecJson instance for CommitId
minor renaming
WIP: writing the function to actually load the metadata it can find
Load and parse Snapshot metadata