Drop memory slightly

Author: devinmatte

ingestor/.chalice/config.json

@@ -92,7 +92,7 @@
         "update_gtfs": {
           "iam_policy_file": "policy-gtfs.json",
           "lambda_timeout": 900,
-          "lambda_memory_size": 8192,
+          "lambda_memory_size": 5120,
           "max_ebs_size_gb": 4
         },
         "update_ridership": {