updated_app.rb

## Updated app.rb

require 'rubygems'
require 'ruby_ttt'
require 'sinatra/base'
require 'shotgun'
require './game_helpers.rb'

class TicTacToe < Sinatra::Base

  configure do
    enable :sessions
    set :session_secret, ENV['SESSION_SECRET'] || 'session secret'
  end

  include GameHelpers

  get '/' do
    session.clear
    erb :index
  end
...
end