Add employee model. Add functionality for access tokens.

Employee endpoint: http://developer.myob.com/api/accountright/v2/contact/employee/

The access token functionality can be used in a controller like this:

    class MYOBSessionController  
      def new
        redirect_to myob_client.get_access_code_url
      end

      def create
        @token = myob_client.get_access_token(params[:code])
        @company_files = myob_client.company_file.all
        # then show the user a view where they can log in to their company file
      end
    end