rebase changes

Author: aileronajay

doc/source/whatsnew/v0.20.0.txt

@@ -59,6 +59,7 @@ Other enhancements
 - ``Series`` provides a ``to_excel`` method to output Excel files (:issue:`8825`)
 - The ``usecols`` argument in ``pd.read_csv`` now accepts a callable function as a value  (:issue:`14154`)
 - ``pd.DataFrame.plot`` now prints a title above each subplot if ``suplots=True`` and ``title`` is a list of strings (:issue:`14753`)
+-  The ``pd.Series.interpolate`` now supports timedelta as index type(:issue:`6424`)
 
 .. _whatsnew_0200.api_breaking: