Update dependencies.

- Update Ruby version to 2.1.5.
- Update numerous gems.
- Add explicit dependency on SleepingKingStudios::Tools.
- Remove implicit dependency on deprecated+removed
SleepingKingStudios::Ext.

Current spec status: 1050 examples, 0 failures in 7.48 seconds.
Add seed data in .yml format via Sprig.
Merge pull request #16 from sleepingkingstudios/upkeep-seeds

Add seed data in .yml format via Sprig.