Miscellaneous updates to appease Rubocop

spec/rails_helper.rb

@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 # This file is copied to spec/ when you run 'rails generate rspec:install'
 require 'spec_helper'
 ENV['RAILS_ENV'] ||= 'test'
 require File.expand_path('../dummy/config/environment', __FILE__)
 # Prevent database truncation if the environment is production
-abort("The Rails environment is running in production mode!") if Rails.env.production?
+abort('The Rails environment is running in production mode!') if Rails.env.production?
 require 'rspec/rails'
 # Add additional requires below this line. Rails is not loaded until this point!