Avoid Kafka 0.10 destabilising the Windows build

Closes gh-12963

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/kafka/KafkaAutoConfigurationIntegrationTests.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,10 +16,13 @@
 
 package org.springframework.boot.autoconfigure.kafka;
 
+import java.io.File;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 import org.junit.After;
+import org.junit.Assume;
+import org.junit.Before;
 import org.junit.ClassRule;
 import org.junit.Test;
 
@@ -49,6 +52,11 @@ public class KafkaAutoConfigurationIntegrationTests {
 
 	private AnnotationConfigApplicationContext context;
 
+	@Before
+	public void doNotRunOnWindows() {
+		Assume.assumeFalse(isWindows());
+	}
+
 	@After
 	public void close() {
 		if (this.context != null) {
@@ -86,6 +94,10 @@ public class KafkaAutoConfigurationIntegrationTests {
 		return applicationContext;
 	}
 
+	private boolean isWindows() {
+		return File.separatorChar == '\\';
+	}
+
 	public static class KafkaConfig {
 
 		@Bean