code: def bot_config
        {
          :consumer_key => ENV["chatterbot_consumer_key"],
          :consumer_secret => ENV["chatterbot_consumer_secret"],
          :access_token => ENV["chatterbot_access_token"],
          :access_token_secret => ENV["chatterbot_access_secret"] || ENV["chatterbot_access_token_secret"]
        }.delete_if { |k, v| v.nil? }.merge(slurp_file(config_file) || {})
      end
docs: bot-specific config settings