in ElasticSuiteCore/Index/IndexSettings.php 'translog.durability' => 'fsync', is invalid

[southerncomputer]

According to Elasticsearch the valid choices are: request or async.

 'translog.durability'    => 'fsync', <-- Needs to be async or request

 public function getInstallIndexSettings()
    {
        $settings = [
            'number_of_replicas'     => $this->helper->getNumberOfReplicas(),
            'refresh_interval'       => self::DIFF_REINDEX_REFRESH_INTERVAL,
            'translog.durability'    => 'async',
            'translog.disable_flush' => false,
        ];

        return $settings;
    }

[afoucret]

PR #176 fix this one.