Test migration to jest by hand

Apparently using regular expressions is way easier.

test/isMap/isMap.test.js

@@ -0,0 +1,8 @@
+const expect = require('expect');
+const isMap = require('./isMap.js');
+
+
+  test('isMap is a Function', () => {
+  expect(isMap).toBeInstanceOf(Function);
+});
+