Change visibility of PersistentEntitiesFactoryBean.

Closes: #1934

Author: christophstrobl

Diff for: src/main/java/org/springframework/data/elasticsearch/config/PersistentEntitiesFactoryBean.java

@@ -29,7 +29,7 @@
  * @author Peter-Josef Meisch
  * @since 4.1
  */
-class PersistentEntitiesFactoryBean implements FactoryBean<PersistentEntities> {
+public class PersistentEntitiesFactoryBean implements FactoryBean<PersistentEntities> {
 
 	private final MappingElasticsearchConverter converter;