Test migration to jest by hand

Apparently using regular expressions is way easier.

test/isArray/isArray.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const isArray = require('./isArray.js');
+
+
+  test('isArray is a Function', () => {
+  expect(isArray).toBeInstanceOf(Function);
+});
+  t.equal(isArray([1]), true, "passed value is an array");
+  t.equal(isArray('array'), false, "passed value is not an array");
+