Tweaks and bugfixes to monitor driver
diff --git a/planetstack/monitor/monitordriver.py b/planetstack/monitor/monitordriver.py
index f7eb1b9..77e8bfd 100644
--- a/planetstack/monitor/monitordriver.py
+++ b/planetstack/monitor/monitordriver.py
@@ -15,5 +15,5 @@
     def __init__(self):
         pass
 
-    def get_meter(self, meter_name, credentials):
+    def get_meter(self, meter_name, obj, pk, credentials=None):
         pass