Update supported elasticsearch version in README.

Author: codingchili

README.md

@@ -21,7 +21,7 @@ The application requires ElasticSearch as its output.
 
 2. Grab the latest .jar file from [releases](https://github.com/codingchili/parser-excel-elasticsearch/releases).
 
-Tested with ElasticSearch 5.6.2 and 6.2.3.
+Tested with ElasticSearch 5.6.2 and 6.4.2.
 
 ## Running
 
@@ -73,4 +73,4 @@ If you want to contribute to this project, open an issue or pull request. :heart
 
 Thanks to JetBrains for providing free open source licenses!
 
-[![](https://algeria20.com/wp-content/uploads/2017/11/jet.png)](http://www.jetbrains.com)
+[![](https://algeria20.com/wp-content/uploads/2017/11/jet.png)](http://www.jetbrains.com)