Upgrade vulcanize to 0.7.6.

node_modules/vulcanize/node_modules/update-notifier/node_modules/configstore/node_modules/js-yaml/lib/js-yaml/type/set.js

Index: node_modules/vulcanize/node_modules/update-notifier/node_modules/configstore/node_modules/js-yaml/lib/js-yaml/type/set.js
diff --git a/node_modules/vulcanize/node_modules/update-notifier/node_modules/configstore/node_modules/js-yaml/lib/js-yaml/type/set.js b/node_modules/vulcanize/node_modules/update-notifier/node_modules/configstore/node_modules/js-yaml/lib/js-yaml/type/set.js
index 5b992185bb81546d194ff236edb695f25faf5061..64d29e9b68c2ed532715ad4b197910804dde46fc 100644
--- a/node_modules/vulcanize/node_modules/update-notifier/node_modules/configstore/node_modules/js-yaml/lib/js-yaml/type/set.js
+++ b/node_modules/vulcanize/node_modules/update-notifier/node_modules/configstore/node_modules/js-yaml/lib/js-yaml/type/set.js
@@ -1,14 +1,15 @@
 'use strict';
 
-
 var Type = require('../type');
 
-
 var _hasOwnProperty = Object.prototype.hasOwnProperty;
 
+function resolveYamlSet(data) {
+  if (null === data) {
+    return true;
+  }
 
-function resolveYamlSet(state) {
-  var key, object = state.result;
+  var key, object = data;
 
   for (key in object) {
     if (_hasOwnProperty.call(object, key)) {
@@ -21,8 +22,12 @@ function resolveYamlSet(state) {
   return true;
 }
 
+function constructYamlSet(data) {
+  return null !== data ? data : {};
+}
 
 module.exports = new Type('tag:yaml.org,2002:set', {
-  loadKind: 'mapping',
-  loadResolver: resolveYamlSet
+  kind: 'mapping',
+  resolve: resolveYamlSet,
+  construct: constructYamlSet
 });