Update license.txt

2020-07-25 08:57:27 +10:00 · 2020-07-25 08:57:27 +10:00 · 410fa80a07
--- a/license.txt
+++ b/license.txt
@ -1,6 +1,6 @@
 MIT License

-Copyright (c) 2018 Simon Cropp
+Copyright (c) .NET Foundation and Contributors

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal