Proxy dev HMR websockets through NGINX (#290)

nginx/conf.d/default.conf

@@ -20,6 +20,8 @@ server {
 
     location / {
         proxy_pass http://10.11.0.3:3004/;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
     }
- 
 }