Refactor theme feature spec
Init engine
Setup rspec
Add blog_app to the Gemfile
Migrate blog tables

Rename tables if they exist and create them if they don't. I had to rename some indexes to keep under the 63 character limit
Convert models/post
Convert models/author
Get blog feature spec passing
Get post/show working
Move ShareView over
Move css into blog_app
Bundle required js
Convert AuthorsController
Install blog_app migrations
Use new markup for archive page
Convert main app to use new blog_app
Fix blog_app assets
Remove blog gems from main app
Migrate taggable_type from Post to BlogApp::Post
Move controller specs into blog_app