Added explicit dependency for `npm install`

diff --git a/extra/package.json b/extra/package.json
new file mode 100644 (file)
index 0000000..ca7ad6b
--- /dev/null
+++ b/extra/package.json
@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "uglify-js": "^2.0.0"
+  }
+}