Use test scope for Mockito (#15)

Author: Kirill Temnenkov

pom.xml

@@ -103,6 +103,7 @@
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
             <version>2.1.0-RC.1</version>
+            <scope>test</scope>
         </dependency>
     </dependencies>