fix security vulnerability

Author: xiaoping6688

package.json

@@ -72,7 +72,7 @@
     "redis": "^2.7.0",
     "request": "^2.81.0",
     "request-promise": "^4.1.1",
-    "sequelize": "^3.30.2",
+    "sequelize": "^5.3.0",
     "serve-favicon": "~2.4.1",
     "sqlite3": "^3.1.8",
     "thrift": "^0.10.0"