Add elasticsearch client to dev dependency

composer.json

@@ -28,13 +28,15 @@
         "php-console/php-console": "^3.1.3",
         "jakub-onderka/php-parallel-lint": "^0.9",
         "predis/predis": "^1.1",
-        "phpspec/prophecy": "^1.6.1"
+        "phpspec/prophecy": "^1.6.1",
+        "elasticsearch/elasticsearch": "^6.0"
     },
     "suggest": {
         "graylog2/gelf-php": "Allow sending log messages to a GrayLog2 server",
         "sentry/sentry": "Allow sending log messages to a Sentry server",
         "doctrine/couchdb": "Allow sending log messages to a CouchDB server",
         "ruflin/elastica": "Allow sending log messages to an Elastic Search server",
+        "elasticsearch/elasticsearch": "Allow sending log messages to an Elastic Search server via official client",
         "php-amqplib/php-amqplib": "Allow sending log messages to an AMQP server using php-amqplib",
         "ext-amqp": "Allow sending log messages to an AMQP server (1.0+ required)",
         "ext-mongodb": "Allow sending log messages to a MongoDB server (via driver)",