Update copyright year 2019 --> 2020.
diff --git a/functions.sh b/functions.sh
index 8a81b8b..254e81c 100755
--- a/functions.sh
+++ b/functions.sh
@@ -1,6 +1,6 @@
 #! /bin/sh
 #
-# Copyright (c) 2018-2019 Gavin D. Howard and contributors.
+# Copyright (c) 2018-2020 Gavin D. Howard and contributors.
 #
 # All rights reserved.
 #