Remove extraneous copyright year.
diff --git a/setup.py b/setup.py
index 7d677b2..da4bf09 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# Copyright 2015-2017 Google Inc. All Rights Reserved.
+# Copyright 2015 Google Inc. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.