Update test to run correctly in Python 3

Author: evanpw

pandas/tests/test_frame.py

@@ -11260,7 +11260,7 @@ def test_clip_against_series(self):
 
         clipped_df = df.clip(lb, ub, axis=0)
 
-        for i in xrange(2):
+        for i in range(2):
             lb_mask = df.iloc[:, i] <= lb
             ub_mask = df.iloc[:, i] >= ub
             mask = ~lb_mask & ~ub_mask