TST: Fix wrong argument in TestDataFrameAlterAxes.test_set_index_dst (pandas-dev#20019)

Author: spacesphere

pandas/tests/frame/test_alter_axes.py

@@ -301,7 +301,7 @@ def test_set_index_timezone(self):
 
     def test_set_index_dst(self):
         di = pd.date_range('2006-10-29 00:00:00', periods=3,
-                           req='H', tz='US/Pacific')
+                           freq='H', tz='US/Pacific')
 
         df = pd.DataFrame(data={'a': [0, 1, 2], 'b': [3, 4, 5]},
                           index=di).reset_index()