Fix session deps

- Change from spring-session to spring-session-core
  and remove use of ExpiringSession.
- Fixes #385

build.gradle

@@ -3,6 +3,7 @@ buildscript {
 		log4jVersion = '1.2.17'
 		springVersion = '5.0.0.BUILD-SNAPSHOT'
 		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
+		springCloudVersion = 'Dalston.BUILD-SNAPSHOT'
 		eclipsePersistenceVersion = '2.1.1'
 		kryoVersion = '3.0.3'
 		springCloudClusterVersion = '1.0.2.RELEASE'
@@ -81,7 +82,7 @@ configure(allprojects) {
 
 	dependencyManagement {
 		imports {
-			mavenBom "org.springframework.cloud:spring-cloud-dependencies:Dalston.BUILD-SNAPSHOT"
+			mavenBom "org.springframework.cloud:spring-cloud-dependencies:$springCloudVersion"
 			mavenBom "org.springframework.boot:spring-boot-dependencies:$springBootVersion"
 		}
 		dependencies {

spring-statemachine-samples/build.gradle

@@ -63,7 +63,7 @@ project('spring-statemachine-samples-web') {
 		compile("org.springframework:spring-webmvc")
 		compile("org.springframework:spring-websocket")
 		compile("org.springframework.security:spring-security-messaging")
-		compile("org.springframework.session:spring-session")
+		compile("org.springframework.session:spring-session-core")
 	}
 }
 

spring-statemachine-samples/web/src/main/java/demo/web/WebSocketConfig.java

@@ -18,7 +18,7 @@ package demo.web;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.messaging.simp.config.MessageBrokerRegistry;
-import org.springframework.session.ExpiringSession;
+import org.springframework.session.MapSession;
 import org.springframework.session.MapSessionRepository;
 import org.springframework.session.web.socket.config.annotation.AbstractSessionWebSocketMessageBrokerConfigurer;
 import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
@@ -26,7 +26,7 @@ import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
 
 @Configuration
 @EnableWebSocketMessageBroker
-public class WebSocketConfig extends AbstractSessionWebSocketMessageBrokerConfigurer<ExpiringSession> {
+public class WebSocketConfig extends AbstractSessionWebSocketMessageBrokerConfigurer<MapSession> {
 
 	@Override
 	protected void configureStompEndpoints(StompEndpointRegistry registry) {