Initial commit of Ruby backend.
Implement more of the Ruby backend.

- Move things around so Sinatra, RSpec, etc. are all happy. Update Procfile accordingly.
- Add Rakefile and .yardopts for Rake and YARD respectively.
- Implement Faction and Factions classes, and start implementing the Api class. Add RSpec tests for factions, corresponding to Testify tests for Python.
- Add a favicon.ico file (yaaaay).
Implement more of the Ruby backend.

- Added classes for people and chapters.
Port remainder of tests from Testify to RSpec.

- Fix bug in Viz3k::Chapters.
Get factions page working with Ruby backend.
Get individual faction pages working with Ruby backend.
Fix bug in Chapters#exists(). Raise StandardError instead of RangeError.
Get coappearance graphs working with Ruby backend.
New favicon.