Upgrade mockito 2.28.2

Author: slandelle

pom.xml

@@ -441,7 +441,7 @@
     <commons-io.version>2.6</commons-io.version>
     <commons-fileupload.version>1.3.3</commons-fileupload.version>
     <privilegedaccessor.version>1.2.2</privilegedaccessor.version>
-    <mockito.version>2.23.4</mockito.version>
+    <mockito.version>2.28.2</mockito.version>
     <hamcrest.version>2.1</hamcrest.version>
     <kerby.version>1.1.1</kerby.version>
   </properties>