Needed to install additional dependency for build to work

Author: Arieg419

package.json

@@ -12,7 +12,8 @@
     "react-dom": "^16.0.0",
     "react-router": "^4.2.0",
     "react-router-dom": "^4.2.2",
-    "react-scripts": "1.0.17"
+    "react-scripts": "1.0.17",
+    "subscriptions-transport-ws": "^0.9.4"
   },
   "scripts": {
     "start": "react-scripts start",