Migrated tests to jest

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

test6/sortedLastIndex/sortedLastIndex.js

@@ -0,0 +1,6 @@
+const sortedLastIndex = (arr, n) => {
+const isDescending = arr[0] > arr[arr.length - 1];
+const index = arr.reverse().findIndex(el => (isDescending ? n <= el : n >= el));
+return index === -1 ? 0 : arr.length - index;
+};
+module.exports = sortedLastIndex;

test6/sortedLastIndex/sortedLastIndex.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const sortedLastIndex = require('./sortedLastIndex.js');
+
+test('Testing sortedLastIndex', () => {
+  //For more information on all the methods supported by tape
+  //Please go to https://github.com/substack/tape
+  expect(typeof sortedLastIndex === 'function').toBeTruthy();
+  expect(sortedLastIndex([10, 20, 30, 30, 40], 30)).toBe(4);
+});