card.rb

class Reward::Card
  def initialize(params)
    @type     = params[:type]
    @username = params[:username]
    @password = params[:password]
  end

  def reward_balance
    case @type
    when "starbucks"
      require 'card_types/starbucks'
      self.card_balance
    when "united"
      require 'card_types/united'
      self.card_balance
    else
      puts "it's not a rewards program I recognize."
    end
  end
end