fix(package): update ws to version 3.1.0 (#4053)

Author: greenkeeper[bot]

package.json

@@ -41,7 +41,7 @@
     "tv4": "1.3.0",
     "winston": "2.3.1",
     "winston-daily-rotate-file": "1.4.6",
-    "ws": "3.0.0"
+    "ws": "3.1.0"
   },
   "devDependencies": {
     "babel-cli": "6.24.1",