reduce timeout: 3min -> 30s

ping.py

@@ -9,6 +9,8 @@ class PingSpider(CrawlSpider):
     name = 'ping'
 
     custom_settings = {
+        # default: 3 min
+        'DOWNLOAD_TIMEOUT': 30, # [s]
         # WORKAROUND
         # [boto] ERROR: Unable to read instance data, giving up
         'DOWNLOAD_HANDLERS': {'s3': None},