Clean up the oopsie. Rebuild the blank exercises.

node_modules/yallist/iterator.js

@@ -1,7 +1,8 @@
-var Yallist = require('./yallist.js')
-
-Yallist.prototype[Symbol.iterator] = function* () {
-  for (let walker = this.head; walker; walker = walker.next) {
-    yield walker.value
+'use strict'
+module.exports = function (Yallist) {
+  Yallist.prototype[Symbol.iterator] = function* () {
+    for (let walker = this.head; walker; walker = walker.next) {
+      yield walker.value
+    }
   }
 }