fix(tests): expectations of some async test where not working (#989)

test/runPromisesInSeries.test.js

@@ -5,5 +5,7 @@ test('runPromisesInSeries is a Function', () => {
 });
 const delay = d => new Promise(r => setTimeout(r, d));
 test('Runs promises in series', () => {
-  runPromisesInSeries([() => delay(100), () => delay(200).then(() => expect(true).toBeTruthy())]);
+  return runPromisesInSeries([() => delay(100), () => delay(200)]).then(() =>
+    expect(true).toBeTruthy()
+  );
 });