Resolves #1.

New (non-database-backed, for now) model in `app/models/blog/blog.rb` returns the hard-coded initial "title" and "subtitle" strings, as specified in *Objects on Rails*' [Yet another frickin' blog app](http://objectsonrails.com/#ID-4886e18d-0f66-4941-83a7-dd07955b194c) page.

RSpec: 25 examples, 0 failures
Script: 0 tests: 0 failures, 0 errors, 0 pending, 0 omitted
RuboCop: 13 files inspected, no offenses detected
RuboCop global overrides in `.rubocop.yml`: 2