supermarket cookbook updates for deployment

* Add test-kitchen support (with BATS test)
* Add linting rake tasks (foodcritic, rubocop)
* Add rubocop configuration
* Add chefignore
* application recipe:
  - install git here instead of separate recipe
  - create [system] user/group for supermarket
  - bundle to vendor directory
* Remove unnecessary recipes
  - editor (dont edit deployed files directly)
  - git (in application recipe)
  - vagrant (use test kitchen)
* Only update apt cache for repositories that are added (improves
  converge time) for node, ruby, redis recipes
* Ensure that the postgresql service is enabled and started always
* Refactor sidekiq config to just marshall out the hash as YAML
* Use shell for environment in env.erb template instead of yaml-ish.