DOC: Include 0.21.1 whatsnew

TomAugspurger · TomAugspurger · commit 2449bb8365a3 · 2017-12-11T20:59:41.000-06:00
diff --git a/doc/source/whatsnew.rst b/doc/source/whatsnew.rst
@@ -18,6 +18,8 @@ What's New
 
 These are new features and improvements of note in each release.
 
+.. include:: whatsnew/v0.21.1.txt
+
 .. include:: whatsnew/v0.21.0.txt
 
 .. include:: whatsnew/v0.20.3.txt
