scripts: Update copyrights

Change-Id: I7dbf24883b90bd54425c6b64592130d8f3b80012
diff --git a/scripts/external_revision_generator.py b/scripts/external_revision_generator.py
index a7992fd..6edb973 100644
--- a/scripts/external_revision_generator.py
+++ b/scripts/external_revision_generator.py
@@ -1,9 +1,9 @@
 #!/usr/bin/env python3
 #
-# Copyright (c) 2015-2017 The Khronos Group Inc.
-# Copyright (c) 2015-2017 Valve Corporation
-# Copyright (c) 2015-2017 LunarG, Inc.
-# Copyright (c) 2015-2017 Google Inc.
+# Copyright (c) 2015-2019 The Khronos Group Inc.
+# Copyright (c) 2015-2019 Valve Corporation
+# Copyright (c) 2015-2019 LunarG, Inc.
+# Copyright (c) 2015-2019 Google Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -37,10 +37,10 @@
         copyright += '\n'
         copyright += '/***************************************************************************\n'
         copyright += ' *\n'
-        copyright += ' * Copyright (c) 2015-2017 The Khronos Group Inc.\n'
-        copyright += ' * Copyright (c) 2015-2017 Valve Corporation\n'
-        copyright += ' * Copyright (c) 2015-2017 LunarG, Inc.\n'
-        copyright += ' * Copyright (c) 2015-2017 Google Inc.\n'
+        copyright += ' * Copyright (c) 2015-2019 The Khronos Group Inc.\n'
+        copyright += ' * Copyright (c) 2015-2019 Valve Corporation\n'
+        copyright += ' * Copyright (c) 2015-2019 LunarG, Inc.\n'
+        copyright += ' * Copyright (c) 2015-2019 Google Inc.\n'
         copyright += ' *\n'
         copyright += ' * Licensed under the Apache License, Version 2.0 (the "License");\n'
         copyright += ' * you may not use this file except in compliance with the License.\n'