Test cleanup and fixes [a-b]

test/mapValues/mapValues.test.js

@@ -9,6 +9,8 @@ const mapValues = require('./mapValues.js');
     fred: { user: 'fred', age: 40 },
     pebbles: { user: 'pebbles', age: 1 }
   };
-  t.deepEqual(mapValues(users, u => u.age), { fred: 40, pebbles: 1 }, 'Maps values');
+  test('Maps values', () => {
+  expect(mapValues(users, u => u.age), { fred: 40, pebbles: 1 }).toEqual()
+});