Make spring-plugin-core a compile dependency so EntityLinks can be used

See gh-2396

Author: wilkinsona

spring-boot-starters/spring-boot-starter-hateoas/pom.xml

@@ -29,7 +29,6 @@
 		<dependency>
 			<groupId>org.springframework.plugin</groupId>
 			<artifactId>spring-plugin-core</artifactId>
-			<scope>runtime</scope>
 		</dependency>
 	</dependencies>
 </project>