add node modules to repo

node_modules/fs-extra/lib/util/assign.js

@@ -0,0 +1,16 @@
+'use strict'
+
+// simple mutable assign
+function assign () {
+  const args = [].slice.call(arguments).filter(i => i)
+  const dest = args.shift()
+  args.forEach(src => {
+    Object.keys(src).forEach(key => {
+      dest[key] = src[key]
+    })
+  })
+
+  return dest
+}
+
+module.exports = assign