修改 readme 版本号

README.md

@@ -59,12 +59,12 @@ MyBatis-Plus is an powerful enhanced toolkit of MyBatis for simplify development
         <dependency>
             <groupId>com.baomidou</groupId>
             <artifactId>mybatis-plus-boot-starter</artifactId>
-            <version>3.1.0</version>
+            <version>3.1.2</version>
         </dependency>
         ```
     -   Gradle
         ```groovy
-        compile group: 'com.baomidou', name: 'mybatis-plus-boot-starter', version: '3.1.0'
+        compile group: 'com.baomidou', name: 'mybatis-plus-boot-starter', version: '3.1.2'
         ```
 -   Modify mapper file extends BaseMapper interface