Upgrade to Elasticsearch 6.3.0

Closes gh-13671

spring-boot-project/spring-boot-autoconfigure/pom.xml

@@ -750,6 +750,11 @@
 			<artifactId>johnzon-jsonb</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-core</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.apache.tomcat.embed</groupId>
 			<artifactId>tomcat-embed-jasper</artifactId>

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -60,7 +60,7 @@
 		<embedded-mongo.version>2.1.1</embedded-mongo.version>
 		<flyway.version>5.0.7</flyway.version>
 		<freemarker.version>2.3.28</freemarker.version>
-		<elasticsearch.version>6.2.4</elasticsearch.version>
+		<elasticsearch.version>6.3.0</elasticsearch.version>
 		<glassfish-el.version>3.0.0</glassfish-el.version>
 		<groovy.version>2.5.0</groovy.version>
 		<gson.version>2.8.5</gson.version>