update node modules

node_modules/clean-css/lib/options/plugins.js

@@ -0,0 +1,25 @@
+function pluginsFrom(plugins) {
+  var flatPlugins = {
+    level1Value: [],
+    level1Property: [],
+    level2Block: []
+  };
+
+  plugins = plugins || [];
+
+  flatPlugins.level1Value = plugins
+    .map(function (plugin) { return plugin.level1 && plugin.level1.value; })
+    .filter(function (plugin) { return plugin != null; });
+
+  flatPlugins.level1Property = plugins
+    .map(function (plugin) { return plugin.level1 && plugin.level1.property; })
+    .filter(function (plugin) { return plugin != null; });
+
+  flatPlugins.level2Block = plugins
+    .map(function (plugin) { return plugin.level2 && plugin.level2.block; })
+    .filter(function (plugin) { return plugin != null; });
+
+  return flatPlugins;
+}
+
+module.exports = pluginsFrom;