Test migration to jest by hand

Apparently using regular expressions is way easier.

test/sortedIndexBy/sortedIndexBy.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const sortedIndexBy = require('./sortedIndexBy.js');
+
+
+  test('sortedIndexBy is a Function', () => {
+  expect(sortedIndexBy).toBeInstanceOf(Function);
+});
+  t.equal(sortedIndexBy([{ x: 4 }, { x: 5 }], { x: 4 }, o => o.x), 0, 'Returns the lowest index to insert the element without messing up the list order');
+  
+