document testing

Author: starenka

README.md

@@ -12,9 +12,13 @@ in the [release](https://github.com/monitora-media/es-utils/releases/latest).
 
 ## Build
 
-    ES_VERSION=8.5.3
+    ES_VERSION=8.9.2
     ./gradlew build -Pelasticsearch.version=$ES_VERSION
 
+## Testing
+
+    gradle test --debug
+
 ## Install
 
     elasticsearch-plugin install file://$(pwd)/build/distributions/monitora_utils-*-SNAPSHOT-$ES_VERSION.zip