Replace retrying with tenacity

As per rholder/retrying#79 retrying is dead. Tenaciy is a community maintained fork.
This also fixes a problem with retry swallowing exceptions.

app.py

@@ -2,11 +2,11 @@
 import logging
 import os
 
-from datetime import datetime, timedelta
 import boto3
 import requests
 import yaml
-from retrying import retry
+from datetime import datetime, timedelta
+from tenacity import retry, wait_fixed, retry_if_result
 
 
 logger = logging.getLogger("app")
@@ -104,7 +104,7 @@ def get_metrics_from_cloudwatch_and_format_for_hostedgraphite(config):
     base_metrics = create_hostedgraphite_base_metrics(config)
     send_to_hostedgraphite("\n".join(base_metrics))
 
-    @retry(wait_fixed=60000, retry_on_result=lambda res: res is None)
+    @retry(wait=wait_fixed(60), retry=retry_if_result(lambda res: res is None))
     def sleep_and_send_retry():
         """Wrapper to apply retry to get and send methods."""
         hostedgraphite_metrics = get_metrics_from_cloudwatch_and_format_for_hostedgraphite(config)

requirements-app.txt

@@ -1,4 +1,4 @@
-retrying==1.3.3
+tenacity==5.0.2
 requests==2.17.3
 PyYAML==3.13
 boto3==1.9.6

requirements.txt

@@ -1,5 +1,5 @@
 # This file is autogenerated. Do not edit it manually.
-retrying==1.3.3
+tenacity==5.0.2
 requests==2.17.3
 PyYAML==3.13
 boto3==1.9.6