Test migration to jest by hand

Apparently using regular expressions is way easier.

test/intersection/intersection.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const intersection = require('./intersection.js');
+
+
+  test('intersection is a Function', () => {
+  expect(intersection).toBeInstanceOf(Function);
+});
+  t.deepEqual(intersection([1, 2, 3], [4, 3, 2]), [2, 3], "Returns a list of elements that exist in both arrays");
+