Update docs for Elasticsearch 5.x and 6.x support

diff --git a/doc/14-features.md b/doc/14-features.md
index 83617df4402ea506cebec48c3f653c38972de233..312b3c8098307526f1c56b1d01ea2418db8e5abe 100644 (file)
--- a/doc/14-features.md
+++ b/doc/14-features.md
@@ -347,7 +347,7 @@ The check results include parsed performance data metrics if enabled.
 
 > **Note**
 >
-> Elasticsearch 5.x+ is required.
+> Elasticsearch 5.x+ is required. This feature has been tested with Elasticsearch 5.6.4 and 6.0.0.
 
 Enable the feature and restart Icinga 2.