Bump elasticsearch-rest-client from 7.6.0 to 7.6.1 in /modules/… (#2401)

Bumps [elasticsearch-rest-client](https://github.com/elastic/elasticsearch) from 7.6.0 to 7.6.1.
- [Release notes](https://github.com/elastic/elasticsearch/releases)
- [Commits](elastic/elasticsearch@v7.6.0...v7.6.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

modules/elasticsearch/build.gradle

@@ -2,6 +2,6 @@ description = "TestContainers :: elasticsearch"
 
 dependencies {
     compile project(':testcontainers')
-    testCompile "org.elasticsearch.client:elasticsearch-rest-client:7.6.0"
+    testCompile "org.elasticsearch.client:elasticsearch-rest-client:7.6.1"
     testCompile "org.elasticsearch.client:transport:6.7.1"
 }