Fix incorrect test for sortedLastIndex snippet

snippets/sortedLastIndex.md

@@ -9,7 +9,7 @@ Use `Array.reverse()` and `Array.findIndex()` to find the appropriate last index
 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 - 1;
+  return index === -1 ? 0 : arr.length - index;
 };
 ```
 

test/sortedLastIndex/sortedLastIndex.js

@@ -1,6 +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 - 1;
+return index === -1 ? 0 : arr.length - index;
 };
 module.exports = sortedLastIndex;

test/sortedLastIndex/sortedLastIndex.test.js

@@ -5,7 +5,7 @@ test('Testing sortedLastIndex', (t) => {
   //For more information on all the methods supported by tape
   //Please go to https://github.com/substack/tape
   t.true(typeof sortedLastIndex === 'function', 'sortedLastIndex is a Function');
-  t.equal(sortedLastIndex([10, 20, 30, 30, 40], 30), 3, 'Returns the highest index to insert the element without messing up the list order');
+  t.equal(sortedLastIndex([10, 20, 30, 30, 40], 30), 4, 'Returns the highest index to insert the element without messing up the list order');
 	//t.deepEqual(sortedLastIndex(args..), 'Expected');
   //t.equal(sortedLastIndex(args..), 'Expected');
   //t.false(sortedLastIndex(args..), 'Expected');