Update elasticsearch/elasticsearch requirement from ~6.1 to ~7.0
Update elasticsearch/elasticsearch requirement from ~6.1 to ~7.0

Updates the requirements on [elasticsearch/elasticsearch](https://github.com/elastic/elasticsearch-php) to permit the latest version.
- [Release notes](https://github.com/elastic/elasticsearch-php/releases)
- [Changelog](https://github.com/elastic/elasticsearch-php/blob/master/CHANGELOG.md)
- [Commits](https://github.com/elastic/elasticsearch-php/compare/v6.1.0...v7.0.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
nailsapp/module-elasticsearch,nailsapp/module-elasticsearch