Merge pull request #17 from ianderse/luke

require rails helper in spec helper, add capybara/rspec require, modify ...
added skeleton for site
fixed merge conflicts
Merge pull request #19 from ianderse/jessica

added skeleton for site
category model, controller, spec
Create user model, controller, validations
Fix merge conflict gemfile and routes
added item_categories for a through table
Add session controller, add user feature tests, update navbar
Merge pull request #32 from ianderse/model-user

Model user
Merge pull request #24 from ianderse/jessica

category model, controller, spec
order and line_item models and migrations and relationships
use decimal for arithmetic precision
actually, not correct to include rails_helper here. the file itself suggests it be kept as light as possible