def add_or_update_gemfile(update_gemfile_if_needed: false)
      if gemfile_exists?
        ensure_gemfile_valid!(update_gemfile_if_needed: update_gemfile_if_needed)
      else
        if update_gemfile_if_needed || UI.confirm("It is recommended to run fastlane with a Gemfile set up, do you want fastlane to create one for you?")
          setup_gemfile!
        end
      end
      return gemfile_path
    end
def add_or_update_gemfile(update_gemfile_if_needed: false)
      if gemfile_exists?
        ensure_gemfile_valid!(update_gemfile_if_needed: update_gemfile_if_needed)
      else
        if update_gemfile_if_needed || UI.confirm("It is recommended to run fastlane with a Gemfile set up, do you want fastlane to create one for you?")
          setup_gemfile!
        end
      end
      return gemfile_path
    end
This method is responsible for ensuring there is a working
 Gemfile, and that `fastlane` is defined as a dependency
 while also having `rubygems` as a gem source