Adding new directories

Adding directories:
app/modules        - it is better to store modules in this directory instead of lib - lib should be left for monkey patching or extending functionality of ruby core (String.to_bool etc.)
app/workers         - put all workers (sidekiq/resque)
app/validations     - put all custom validation classes there
Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.