update mockito to fix failing test

yue9944882 · yue9944882 · commit 6281064c8161 · 2019-07-25T19:06:44.000+08:00
diff --git a/util/pom.xml b/util/pom.xml
@@ -92,7 +92,7 @@
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>2.13.0</version>
+            <version>2.23.4</version>
             <scope>test</scope>
         </dependency>
         <dependency>
