add name checking for multilevel index reset

Author: minggli

pandas/tests/test_multilevel.py

@@ -745,9 +745,11 @@ def test_reset_index_with_drop(self):
         deleveled = self.series.reset_index()
         assert isinstance(deleveled, DataFrame)
         assert len(deleveled.columns) == len(self.series.index.levels) + 1
+        assert deleveled.index.name == self.series.index.name
 
         deleveled = self.series.reset_index(drop=True)
         assert isinstance(deleveled, Series)
+        assert deleveled.index.name == self.series.index.name
 
     def test_count_level(self):
         def _check_counts(frame, axis=0):