Add "version" field to IndicesGetTemplateResponse (#509)
Add "version" field to IndicesGetTemplateResponse (#509)

As per the Elasticsearch docs[0], you can provide a "version" field that
is used for external management of templates.  This adds the field to
the response message so it can be read.

[0]: https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-templates.html#versioning-templates
guilherme-santos/elastic,olivere/elastic,olivere/elastic,guilherme-santos/elastic