ElasticContainer: Test with versions 5.6.13 and 6.4.3

Change-Id: I242972a06800798b6ad449109d765ac21f27d8b5
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/testing/ElasticContainer.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/testing/ElasticContainer.java
index e347f75..0b6e3ee 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/testing/ElasticContainer.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/testing/ElasticContainer.java
@@ -46,13 +46,13 @@
       case V2_4:
         return "elasticsearch:2.4.6-alpine";
       case V5_6:
-        return "docker.elastic.co/elasticsearch/elasticsearch:5.6.12";
+        return "docker.elastic.co/elasticsearch/elasticsearch:5.6.13";
       case V6_2:
         return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.2.4";
       case V6_3:
         return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.3.2";
       case V6_4:
-        return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.4.2";
+        return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.4.3";
     }
     throw new IllegalStateException("No tests for version: " + version.name());
   }