added tests for experience tracking module

refactored some things in experience tracking
changed the paging behaviour for leader board and added check for negative numbers
fixed rank not being correct for further pages
added test-common module to have some common code für tests
fixed command creation

abstracto-application/abstracto-modules/experience-tracking/experience-tracking-impl/pom.xml

@@ -17,6 +17,14 @@
             <artifactId>experience-tracking-int</artifactId>
             <version>${project.version}</version>
         </dependency>
+
+        <dependency>
+            <groupId>dev.sheldan.abstracto</groupId>
+            <artifactId>test-commons</artifactId>
+            <version>${project.version}</version>
+            <type>test-jar</type>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
 </project>