slight changes to package structure + naming

src/main/java/mops/gruppen2/service/GroupService.java

@@ -0,0 +1,16 @@
+package mops.gruppen2.service;
+
+import mops.gruppen2.domain.Group;
+import mops.gruppen2.domain.event.Event;
+import org.springframework.stereotype.Service;
+import java.util.List;
+
+@Service
+public class GroupService {
+
+	Group buildGroup(List<Event> eventList){
+		Group newGroup = new Group();
+		eventList.forEach(newGroup::applyEvent);
+		return newGroup;
+	}
+}