More descriptive error message when failing to start collector

cirron/cirron.py

@@ -58,7 +58,7 @@ def __init__(self):
     def __enter__(self):
         ret_val = Collector.cirron_lib.start()
         if ret_val == -1:
-            raise Exception("Failed to start collector.")
+            raise Exception("Failed to start collector. Make sure you have the right permissions, you might need to use sudo.")
         self._fd = ret_val
 
         return self