Renew ROC key on expiration

Change-Id: Ie07e8822e8392b61787b4c10f38f6e2970135810
diff --git a/roc.py b/roc.py
index 87ba152..b193a2a 100644
--- a/roc.py
+++ b/roc.py
@@ -106,7 +106,12 @@
             log.error("ROC request timeout, error={}".format(e))
             sys.exit()
         if response.status_code != 200:
-            log.error("get_devicegroups() failed, status_code: {}".format(response.status_code))
+            log.info("Renew ROC api key")
+            self.key = self.get_key()
+            response = requests.get(url, headers=self.headers(), timeout=10)
+            if response.status_code != 200:
+                log.error("get_devicegroups() failed, status_code: {}".format(response.status_code))
+                sys.exit()
             return None
         return json.loads(response.text)['device-group']