Test cleanup and fixes [c-d]

test/reverseString/reverseString.test.js

@@ -5,5 +5,7 @@ const reverseString = require('./reverseString.js');
   test('reverseString is a Function', () => {
   expect(reverseString).toBeInstanceOf(Function);
 });
-  t.equal(reverseString('foobar'), 'raboof', "Reverses a string.");
+  test('Reverses a string.', () => {
+  expect(reverseString('foobar')).toBe('raboof')
+});