Refactor (various fixes for rails_best_practices and rubocop)

__Notes:__
- This is the first in a series of pull requests of the refactor branch, because I have a _lot_ of work to do and I want to integrate it into master several times before everything is fully completed.
- You'll probably want to download and run the rails_best_practices and rubocop gems.
- Rubocop's config file is currently a todo list. This means that the config file is set to ignore any types of issues that I haven't fixed yet. If you want to actually see the number of rubocop offenses we have, delete `.rubocop.yml` first.