Add core dependency back to Hystrix starter or else starter wont include Hystrix implementation.

spring-cloud-starter-netflix/spring-cloud-starter-netflix-hystrix/pom.xml

@@ -22,6 +22,10 @@
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-starter</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-netflix-core</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-netflix-ribbon</artifactId>