Migrated tests to jest

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

test6/sortedIndexBy/sortedIndexBy.js

@@ -0,0 +1,7 @@
+const sortedIndexBy = (arr, n, fn) => {
+const isDescending = fn(arr[0]) > fn(arr[arr.length - 1]);
+const val = fn(n);
+const index = arr.findIndex(el => (isDescending ? val >= fn(el) : val <= fn(el)));
+return index === -1 ? arr.length : index;
+};
+module.exports = sortedIndexBy;

test6/sortedIndexBy/sortedIndexBy.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const sortedIndexBy = require('./sortedIndexBy.js');
+
+test('Testing sortedIndexBy', () => {
+  //For more information on all the methods supported by tape
+  //Please go to https://github.com/substack/tape
+  expect(typeof sortedIndexBy === 'function').toBeTruthy();
+  expect(sortedIndexBy([{ x: 4 }, { x: 5 }], { x: 4 }, o => o.x)).toBe(0);
+});