add druid springboot starter version manager

pom.xml

@@ -286,6 +286,11 @@
                     </exclusion>
                 </exclusions>
             </dependency>
+            <dependency>
+                <groupId>com.alibaba</groupId>
+                <artifactId>druid-spring-boot-starter</artifactId>
+                <version>${druid.version}</version>
+            </dependency>
 
             <!-- apollo -->
             <dependency>