Test migration to jest by hand

Apparently using regular expressions is way easier.

test/defer/defer.js

@@ -0,0 +1,2 @@
+const defer = (fn, ...args) => setTimeout(fn, 1, ...args);
+module.exports = defer;

test/defer/defer.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const defer = require('./defer.js');
+
+
+  test('defer is a Function', () => {
+  expect(defer).toBeInstanceOf(Function);
+});
+  t.pass('Tested by @chalarangelo on 16/02/2018');
+  
+