fix(package): update lru-cache to version 5.1.1

Closes #5189

Author: greenkeeper[bot]

package.json

@@ -31,7 +31,7 @@
     "follow-redirects": "1.5.9",
     "intersect": "1.0.1",
     "lodash": "4.17.11",
-    "lru-cache": "4.1.4",
+    "lru-cache": "5.1.1",
     "mime": "2.3.1",
     "mongodb": "3.1.10",
     "parse": "2.1.0",