Install jstat.

Author: Frank

package-lock.json

@@ -27,6 +27,7 @@
     "express-session": "^1.17.1",
     "express-useragent": "^1.0.15",
     "geoip-lite": "^1.4.2",
+    "jstat": "^1.9.4",
     "mongoose": "^5.9.18",
     "morgan": "^1.10.0",
     "nodemon": "^2.0.4",