Merge pull request webtorrent#246 from webtorrent/greenkeeper/ws-4.0.0

Update ws to the latest version 🚀

Author: DiegoRBaquero

package.json

@@ -41,7 +41,7 @@
     "string2compact": "^1.1.1",
     "uniq": "^1.0.1",
     "unordered-array-remove": "^1.0.2",
-    "ws": "^3.3.1",
+    "ws": "^4.0.0",
     "xtend": "^4.0.0"
   },
   "devDependencies": {