Set release date

oschwald · oschwald · commit 3fa909c03bbe · 2020-07-21T10:50:33.000-07:00
diff --git a/HISTORY.rst b/HISTORY.rst
@@ -3,7 +3,7 @@
 History
 -------
 
-4.0.0
+4.0.0 (2020-07-21)
 ++++++++++++++++++
 
 * IMPORTANT: Python 2.7 and 3.5 support has been dropped. Python 3.6 or greater
