Update Copyright (#76)

Bunp the copyright notices to keep them in date.

Author: spjmurray

cmd/broker/main.go

@@ -1,4 +1,4 @@
-// Copyright 2020 Couchbase, Inc.
+// Copyright 2020-2021 Couchbase, Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file  except in compliance with the License.