Fix some python2-isms in prep for python3

These ones should work in both versions so we don't have to do them as
part of a global change over.

Change-Id: I2177b329d385c50d706a50a750b6c115ea3ea7ae
diff --git a/y2017/control_loops/python/hood.py b/y2017/control_loops/python/hood.py
index 58bd15e..7f875c9 100755
--- a/y2017/control_loops/python/hood.py
+++ b/y2017/control_loops/python/hood.py
@@ -230,7 +230,7 @@
         profile.SetGoal(goal[0, 0])
 
         U_last = numpy.matrix(numpy.zeros((1, 1)))
-        for i in xrange(iterations):
+        for i in range(iterations):
             observer_hood.Y = hood.Y
             observer_hood.CorrectObserver(U_last)