LICENSE,docs: Update copyright year range to include 2021.

Signed-off-by: Damien George <damien@micropython.org>

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2013-2020 Damien P. George
+Copyright (c) 2013-2021 Damien P. George
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

docs/conf.py

@@ -66,7 +66,7 @@ master_doc = 'index'
 
 # General information about the project.
 project = 'MicroPython'
-copyright = '2014-2020, Damien P. George, Paul Sokolovsky, and contributors'
+copyright = '2014-2021, Damien P. George, Paul Sokolovsky, and contributors'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the