update mockito-core
diff --git a/pom.xml b/pom.xml
index 706a8d1..8efaed4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -252,7 +252,7 @@
     <dependency>
       <groupId>org.mockito</groupId>
       <artifactId>mockito-core</artifactId>
-      <version>2.18.3</version>
+      <version>2.28.2</version>
       <scope>test</scope>
     </dependency>
   </dependencies>