Fixes linting errors in spec files

src/app/quiz/quiz-flow/confidence-rate/confidence-rate.component.spec.ts

@@ -61,7 +61,7 @@ describe('QuizFlow: ConfidenceRateComponent', () => {
           provide: QuizService,
           useValue: {
             quizUpdateEmitter: of(null),
-            loadDataToPlay: () => new Promise(resolve => resolve()),
+            loadDataToPlay: () => new Promise<void>(resolve => resolve()),
           },
         }, HeaderLabelService, {
           provide: ThemesService,
@@ -105,7 +105,7 @@ describe('QuizFlow: ConfidenceRateComponent', () => {
   }));
 
   it('#sendConfidence', waitForAsync(() => {
-    spyOn(component, 'sendConfidence').and.callFake(() => new Promise<Subscription>(resolve => resolve()));
+    spyOn(component, 'sendConfidence').and.callFake(() => new Promise<Subscription>(resolve => resolve(null)));
 
     component.sendConfidence();
 

src/app/root/nickname-chooser/nickname-input/nickname-input.component.spec.ts

@@ -53,7 +53,7 @@ describe('NicknameInputComponent', () => {
         }, {
           provide: QuizService,
           useValue: {
-            loadDataToPlay: () => new Promise(resolve => resolve()),
+            loadDataToPlay: () => new Promise<void>(resolve => resolve()),
             quiz: {},
           },
         }, {
@@ -110,7 +110,7 @@ describe('NicknameInputComponent', () => {
   describe('#joinQuiz', () => {
 
     it('should join the quiz', waitForAsync(inject([Router], (router: Router) => {
-      spyOn(router, 'navigate').and.callFake(() => new Promise<boolean>(resolve => {resolve(); }));
+      spyOn(router, 'navigate').and.callFake(() => new Promise<boolean>(resolve => resolve(false)));
 
       component.joinQuiz();