Bring Python into the next decade. (GH-17801)

diff --git a/LICENSE b/LICENSE
index 9dc010d..66a3ac8 100644
--- a/LICENSE
+++ b/LICENSE
@@ -73,7 +73,7 @@
 distribute, and otherwise use Python alone or in any derivative version,
 provided, however, that PSF's License Agreement and PSF's notice of copyright,
 i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
-2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Python Software Foundation;
+2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Python Software Foundation;
 All Rights Reserved" are retained in Python alone or in any derivative version
 prepared by Licensee.