fix(package): update @types/node to version 8.0.31 (#833)

package.json

@@ -107,7 +107,7 @@
   "dependencies": {
     "@types/express": "4.0.37",
     "@types/ws": "3.0.2",
-    "@types/node": "8.0.30",
+    "@types/node": "8.0.31",
     "bl": "1.2.1",
     "body-parser": "1.18.2",
     "chromedriver": "2.32.3",