Fix.

node_modules/unset-value/index.js

@@ -0,0 +1,32 @@
+/*!
+ * unset-value <https://github.com/jonschlinkert/unset-value>
+ *
+ * Copyright (c) 2015, 2017, Jon Schlinkert.
+ * Released under the MIT License.
+ */
+
+'use strict';
+
+var isObject = require('isobject');
+var has = require('has-value');
+
+module.exports = function unset(obj, prop) {
+  if (!isObject(obj)) {
+    throw new TypeError('expected an object.');
+  }
+  if (obj.hasOwnProperty(prop)) {
+    delete obj[prop];
+    return true;
+  }
+
+  if (has(obj, prop)) {
+    var segs = prop.split('.');
+    var last = segs.pop();
+    while (segs.length && segs[segs.length - 1].slice(-1) === '\\') {
+      last = segs.pop().slice(0, -1) + '.' + last;
+    }
+    while (segs.length) obj = obj[prop = segs.shift()];
+    return (delete obj[last]);
+  }
+  return true;
+};