Bump mockserver-netty from 5.1.1 to 5.6.1

Change-Id: Ie8648bc2bae3ac095fa7a923d478f31dabb39ce5
diff --git a/pom.xml b/pom.xml
index ac49436..2017c4f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -86,7 +86,7 @@
     <dependency>
       <groupId>org.mock-server</groupId>
       <artifactId>mockserver-netty</artifactId>
-      <version>5.1.1</version>
+      <version>5.6.1</version>
       <scope>test</scope>
     </dependency>
 
diff --git a/src/test/java/de/ids_mannheim/korap/plkexport/ServiceTest.java b/src/test/java/de/ids_mannheim/korap/plkexport/ServiceTest.java
index 0142ab3..ec229d3 100644
--- a/src/test/java/de/ids_mannheim/korap/plkexport/ServiceTest.java
+++ b/src/test/java/de/ids_mannheim/korap/plkexport/ServiceTest.java
@@ -8,8 +8,7 @@
 
 // Mockserver tests
 import org.mockserver.integration.ClientAndServer;
-import org.mockserver.client.server.MockServerClient;
-import org.mockserver.junit.MockServerRule;
+import org.mockserver.client.MockServerClient;
 import static org.mockserver.model.HttpRequest.*;
 import static org.mockserver.model.HttpResponse.*;
 import org.junit.Before;