util|scrooge|finagle|twitter-server|finatra - Update READMEs

Problem/Solution

Ensure all the README files have a license with copyright date
section. Update the date to 2020 (finally). Fix up Finatra
Thrift example to the latest code.

Differential Revision: https://phabricator.twitter.biz/D505486

README.md

@@ -45,3 +45,9 @@ TwitterServer, and weekly snapshots are published to the `develop` branch. In ge
 pull requests should be submitted against `develop`. See
 [CONTRIBUTING.md](https://github.com/twitter/twitter-server/blob/master/CONTRIBUTING.md)
 for more details about how to contribute.
+
+## License
+
+Copyright 2013-2020 Twitter, Inc.
+
+Licensed under the Apache License, Version 2.0: https://www.apache.org/licenses/LICENSE-2.0