Test migration to jest by hand

Apparently using regular expressions is way easier.

test/pickBy/pickBy.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const pickBy = require('./pickBy.js');
+
+
+  test('pickBy is a Function', () => {
+  expect(pickBy).toBeInstanceOf(Function);
+});
+  t.deepEqual(pickBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'), { 'a': 1, 'c': 3 }, 'Creates an object composed of the properties the given function returns truthy for.');
+  
+