elasticsearch 버전별 호환체크해두기, pom 버전 확인

[참조] docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/#core.extensions

spring data release train	spring data elasticsearch	Elasticsearch	Spring boot
2020.0.0[1]	4.1.x[1]	7.9.3	2.3.x[1]
Neumann	4.0.x	7.6.2	2.3.x
Moore	3.2.x	6.8.12	2.2.x
Lovelace	3.1.x	6.2.2	2.1.x
Kay[2]	3.0.x[2]	5.5.0	2.0.x[2]
Ingalls[2]	2.1.x[2]	2.4.0	1.5.x[2]

spring boot 기반에서 세팅하려고 함으로 2.3.x 버전을 설치 해야함

pom.xml<--  추가

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
	<version>2.3.2.RELEASE</version>
</dependency>