Bring documentation into line with master branch.

Author: ri938

doc/source/whatsnew/v0.20.3.txt

@@ -42,12 +42,7 @@ Bug Fixes
 - Fixed compat with loading a ``DataFrame`` with a ``PeriodIndex``, from a ``format='fixed'`` HDFStore, in Python 3, that was written in Python 2 (:issue:`16781`)
 - Fixed a bug in failing to compute rolling computations of a column-MultiIndexed ``DataFrame`` (:issue:`16789`, :issue:`16825`)
 - Bug in a DataFrame/Series with a ``TimedeltaIndex`` when slice indexing (:issue:`16637`)
-- Fixed a pytest marker failing downstream packages' tests suites (:issue:`16680`)
-- Fixed compat with loading a ``DataFrame`` with a ``PeriodIndex``, from a ``format='fixed'`` HDFStore, in Python 3, that was written in Python 2 (:issue:`16781`)
-- Fixed a pytest marker failing downstream packages' tests suites (:issue:`16680`)
-- Bug in reindexing on an empty ``CategoricalIndex`` (:issue:`16770`)
-- Fixed bug where computing the rolling covariance of a MultiIndexed ``DataFrame`` improperly raised a ``ValueError`` (:issue:`16789`)
-- Fixed a bug in failing to compute rolling computations of a column-MultiIndexed ``DataFrame`` (:issue:`16789`, :issue:`16825`)
+
 
 Conversion
 ^^^^^^^^^^
@@ -103,4 +98,4 @@ Categorical
 - Bug in ``DataFrame.sort_values`` not respecting the ``kind`` with categorical data (:issue:`16793`)
 
 Other
-^^^^^
+^^^^^