fix failing tests

src/test/java/nl/tudelft/submit/service/grading/ModuleGradingTest.java

@@ -81,7 +81,7 @@ public class ModuleGradingTest {
 	private static final ModuleGradingFormula MODULE_FORMULA = ModuleGradingFormula.builder()
 			.entityId(MODULE_ID_DTO)
 			.type(GradeScheme.DUTCH_GRADE)
-			.formula("assignment").build();
+			.formula("var_assignment").build();
 
 	private static final Long PERSON_ID = 232232L;
 	private static final PersonIdDTO PERSON_ID_DTO = new PersonIdDTO().id(PERSON_ID);