Updated the test system

test/omitBy.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const {omitBy} = require('./_30s.js');
+
+test('omitBy is a Function', () => {
+  expect(omitBy).toBeInstanceOf(Function);
+});
+test('Creates an object composed of the properties the given function returns falsey for', () => {
+  expect(omitBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number')).toEqual({ b: '2' });
+});