Add tests for Lab model

What does this mr do?

This MR adds tests for the Lab model

src/main/java/nl/tudelft/ewi/queue/controller/CourseController.java

@@ -96,9 +96,6 @@ public class CourseController {
 	@Autowired
 	private AssignmentRepository assignmentRepository;
 
-	@Autowired
-	private FirstYearMentorGroupRepository firstYearMentorGroupRepository;
-
 	@Autowired
 	private ParticipantValidator participantValidator;
 
@@ -431,8 +428,8 @@ public class CourseController {
 		model.addAttribute("course", course);
 		model.addAttribute("labs", labs);
 		model.addAttribute("occupation", numberOfAvailableSlotsStrings(course));
-		if (course.getHasGroups() && firstYearMentorGroupRepository.findAllByActiveIsTrue().size() == 0) {
-			model.addAttribute("alert", "No mentor groups have yet to be imported.");
+		if (course.getHasGroups() && course.getGroups().size() == 0) {
+			model.addAttribute("alert", "No groups have yet been imported.");
 		}
 
 		return "course/view/labs";