updating copyright 2020, signalsciences/sigsci#20819

Author: nathan

LICENSE.md

@@ -2,7 +2,7 @@
 
 The MIT License (MIT)
 
-Copyright (c) 2019 Signal Sciences Corp.
+Copyright (c) 2019-2020 Signal Sciences Corp.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal