[Docs] Update Copyright notices to 2018 (#29404)

NOTICE.txt

@@ -1,5 +1,5 @@
 Elasticsearch
-Copyright 2009-2017 Elasticsearch
+Copyright 2009-2018 Elasticsearch
 
 This product includes software developed by The Apache Software
 Foundation (http://www.apache.org/).

distribution/packages/src/deb/copyright

@@ -1,4 +1,4 @@
-Copyright 2013-2016 Elasticsearch <info@elastic.co>
+Copyright 2013-2018 Elasticsearch <info@elastic.co>
 
 License: Apache-2.0
  Licensed under the Apache License, Version 2.0 (the "License");

docs/java-rest/license.asciidoc

@@ -1,6 +1,6 @@
 == License
 
-Copyright 2013-2017 Elasticsearch
+Copyright 2013-2018 Elasticsearch
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

docs/perl/index.asciidoc

@@ -115,7 +115,7 @@ https://github.com/elastic/elasticsearch-perl/blob/master/CONTRIBUTING.asciidoc[
 
 == Copyright and License
 
-This software is Copyright (c) 2013-2016 by Elasticsearch BV.
+This software is Copyright (c) 2013-2018 by Elasticsearch BV.
 
 This is free software, licensed under:
 https://github.com/elastic/elasticsearch-perl/blob/master/LICENSE.txt[The Apache License Version 2.0].

docs/python/index.asciidoc

@@ -120,7 +120,7 @@ some of the more engaging tasks like bulk indexing and reindexing.
 
 === License
 
-Copyright 2013-2017 Elasticsearch
+Copyright 2013-2018 Elasticsearch
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

docs/ruby/copyright.asciidoc

@@ -1,5 +1,5 @@
 == Copyright and License
 
-This software is Copyright (c) 2013-2016 by Elasticsearch BV.
+This software is Copyright (c) 2013-2018 by Elasticsearch BV.
 
 This is free software, licensed under The Apache License Version 2.0.