add mockito dependency

Author: fmbenhassine

pom.xml

@@ -127,6 +127,12 @@
             <version>3.5.2</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>2.2.25</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
 </project>