chore(package): update lru-cache to version 4.0.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -100,7 +100,7 @@
     "escape-regexp-component": "^1.0.2",
     "formidable": "^1.0.17",
     "http-signature": "^0.11.0",
-    "lru-cache": "^2.6.5",
+    "lru-cache": "^4.0.1",
     "mime": "^1.3.4",
     "once": "^1.3.2",
     "qs": "^5.2.0",