install gulp to process code

node_modules/liftoff/lib/file_search.js

@@ -0,0 +1,14 @@
+var findup = require('findup-sync');
+
+module.exports = function (search, paths) {
+  var path;
+  var len = paths.length;
+  for (var i = 0; i < len; i++) {
+    if (path) {
+      break;
+    } else {
+      path = findup(search, { cwd: paths[i], nocase: true });
+    }
+  }
+  return path;
+};