lib/apigw/logger.rb
def perform_request(http, env)
      http_response = super
      env[:http_version] = http_response.http_version
      env[:message] = http_response.message
      http_response
    end
def perform_request(http, env)
      http_response = super
      env[:http_version] = http_response.http_version
      env[:message] = http_response.message
      http_response
    end
オーバーライドして :http_version と :message をenvに入れておく