Migrated tests to jest

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

test3/intersectionBy/intersectionBy.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const intersectionBy = require('./intersectionBy.js');
+
+test('Testing intersectionBy', () => {
+  //For more information on all the methods supported by tape
+  //Please go to https://github.com/substack/tape
+  expect(typeof intersectionBy === 'function').toBeTruthy();
+  expect(intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor)).toEqual([2.1]);
+});