Update License dates

Noah Berman · Noah Berman · commit 04e15ffa4c4f · 2019-02-27T11:47:21.000+01:00
diff --git a/LICENSE.txt b/LICENSE.txt
@@ -1,4 +1,4 @@
-Copyright (c) 2014-2018 SendGrid, Inc.
+Copyright (c) 2014-2019 SendGrid, Inc.
 
 MIT License
 
