Migrated tests to jest

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

test4/omit/omit.js

@@ -0,0 +1,5 @@
+const omit = (obj, arr) =>
+Object.keys(obj)
+.filter(k => !arr.includes(k))
+.reduce((acc, key) => ((acc[key] = obj[key]), acc), {});
+module.exports = omit;

test4/omit/omit.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const omit = require('./omit.js');
+
+test('Testing omit', () => {
+  //For more information on all the methods supported by tape
+  //Please go to https://github.com/substack/tape
+  expect(typeof omit === 'function').toBeTruthy();
+  expect(omit({ a: 1, b: '2', c: 3 }, ['b'])).toEqual({ 'a': 1, 'c': 3 });
+});