Todd Sundsted

Fix the Redis configuration throughout the code. Heroku wants to specify the Redis connection as a URL, so find `REDIS_HOST` and `REDIS_PORT` pairs and replace them with something like `url: ENV['REDIS_URL']`. Do this in `config/cable.yml`, `config/environments/production.rb`, `config/initializers/redis.rb` and `config/initializers/sidekiq.rb`.