update to python3

Change the python file to explicitly indicate python3.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Change-Id: I686c7c6a415e0c74daa6c40e9da37f9808588556
diff --git a/sensor_gen.py b/sensor_gen.py
index bedf4f8..e53c62d 100755
--- a/sensor_gen.py
+++ b/sensor_gen.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import yaml