Elasticsearch 6.1.0 released

Elasticsearch 6.1.0, based on Lucene 7.1.0, introduces several noteworthy features and improvements, including the Split Index API for efficient index splitting, composite aggregation for comprehensive data retrieval, and adaptive replica selection to enhance search request efficiency. This release also improves indexing throughput by optimizing the exists query and introduces scripted similarities for customizable scoring. Additionally, it updates Watcher to execute tasks with the privileges of the user who created or last updated a watch, ensuring more secure and controlled access. These updates collectively aim to enhance performance, flexibility, and security for Elasticsearch users, encouraging feedback and engagement from the community.