将httpclient显式进行依赖，以便于客户端优先使用配置的版本

Author: binarywang

pom.xml

@@ -97,6 +97,11 @@
       <version>${logback.version}</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.httpcomponents</groupId>
+      <artifactId>httpclient</artifactId>
+      <version>${httpclient.version}</version>
+    </dependency>
     <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpmime</artifactId>