update copyright notices to reflect changes made this year

app/price_view.py

@@ -1,5 +1,5 @@
 #
-# Copyright (c) Daniel Sheffield 2021
+# Copyright (c) Daniel Sheffield 2021 - 2022
 #
 # All rights reserved
 #

app/txn_view.py

@@ -1,5 +1,5 @@
 #
-# Copyright (c) Daniel Sheffield 2021
+# Copyright (c) Daniel Sheffield 2021 - 2022
 #
 # All rights reserved
 #