add lost dependency of sc 2020

spring-cloud-alibaba-examples/nacos-example/nacos-discovery-example/nacos-discovery-consumer-example/pom.xml

@@ -41,6 +41,10 @@
             <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

spring-cloud-alibaba-examples/sentinel-example/sentinel-feign-example/sentinel-feign-consumer-example/pom.xml

@@ -42,6 +42,11 @@
             <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
+        </dependency>
+
     </dependencies>
 
     <build>

spring-cloud-alibaba-examples/spring-cloud-alibaba-dubbo-examples/spring-cloud-dubbo-provider-sample/pom.xml

@@ -133,6 +133,11 @@
             <artifactId>hibernate-validator</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-bootstrap</artifactId>
+        </dependency>
+
     </dependencies>
 
     <build>