fix(package): update socket.io-client to version 2.1.1

Closes #560

Author: greenkeeper[bot]

package.json

@@ -103,7 +103,7 @@
     "primeng": "2.0.3",
     "primeui": "4.1.15",
     "rxjs": "^5.4.3",
-    "socket.io-client": "2.0.4",
+    "socket.io-client": "2.1.1",
     "zone.js": "0.7.8"
   },
   "devDependencies": {