spring-cloud问题排查

### 问题1报错，应用无法启动
org.springframework.core.io.ClassPathResource.getInputStream()抛出异常:

FileNotFoundException：org/springframework/boot/actuate/autoconfigure/HealthIndicatorAutoConfiguration.class cannot be opened because it does not exist



### 原因分析
HealthIndicatorAutoConfiguration 在spring-boot不同版本路径变了
- spring-boot1.x: org.springframework.boot.actuate.autoconfigure.HealthIndicatorAutoConfiguration
- spring-boot2.x：org.springframework.boot.actuate.autoconfigure.health.HealthIndicatorAutoConfiguration


通过debug发现，源头在 HystrixAutoConfiguration，代码如下：

```java
import org.springframework.boot.actuate.autoconfigure.HealthIndicatorAutoConfiguration;
@Configuration
@ConditionalOnClass({ Hystrix.class, HealthIndicator.class })
@AutoConfigureAfter({ HealthIndicatorAutoConfiguration.class })
public class HystrixAutoConfiguration {

}
```
HystrixAutoConfiguration依赖的是spring-boot1.x版本的HealthIndicatorAutoConfiguration，通过升级spring-cloud版本，问题解决。



### 问题2
同样的问题出现在 org/springframework/cloud/netflix/eureka/EurekaClientAutoConfiguration.class

需要分析出 org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration被谁用到的。
通过debug发现，在 AutoConfigurationSorter.addToClasses() 发现是org.springframework.cloud.netflix.ribbon.RibbonAutoConfiguration引入的，代码如下：

```java
package org.springframework.cloud.netflix.ribbon;

@Configuration
@Conditional(RibbonAutoConfiguration.RibbonClassesConditions.class)
@RibbonClients
@AutoConfigureAfter(name = "org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration")
@AutoConfigureBefore({LoadBalancerAutoConfiguration.class, AsyncLoadBalancerAutoConfiguration.class})
@EnableConfigurationProperties({RibbonEagerLoadProperties.class, ServerIntrospectorProperties.class})
public class RibbonAutoConfiguration {

}
```
可以发现是同样的原因，实际上我们不会使用到RibbonAutoConfiguration，排除掉spring-cloud-netflix-ribbon，问题解决