Migrated tests to jest

Used jest-codemods to migrate, will have to pass everything by hand before we can merge.

test4/mapValues/mapValues.test.js

@@ -0,0 +1,13 @@
+const expect = require('expect');
+const mapValues = require('./mapValues.js');
+
+test('Testing mapValues', () => {
+  //For more information on all the methods supported by tape
+  //Please go to https://github.com/substack/tape
+  expect(typeof mapValues === 'function').toBeTruthy();
+  const users = {
+    fred: { user: 'fred', age: 40 },
+    pebbles: { user: 'pebbles', age: 1 }
+  };
+  expect(mapValues(users, u => u.age)).toEqual({ fred: 40, pebbles: 1 });
+});