fix(package): update ws to version 6.0.0 (#609)

Closes #599

Author: flovilmart

package.json

@@ -29,7 +29,7 @@
   },
   "dependencies": {
     "babel-runtime": "6.26.0",
-    "ws": "5.2.1",
+    "ws": "6.0.0",
     "xmlhttprequest": "1.8.0"
   },
   "devDependencies": {