install gulp to process code

node_modules/is-relative/index.js

@@ -0,0 +1,12 @@
+'use strict';
+
+var isUncPath = require('is-unc-path');
+
+module.exports = function isRelative(filepath) {
+  if (typeof filepath !== 'string') {
+    throw new TypeError('expected filepath to be a string');
+  }
+
+  // Windows UNC paths are always considered to be absolute.
+  return !isUncPath(filepath) && !/^([a-z]:)?[\\\/]/i.test(filepath);
+};