Fix authenticate ws before connection bug

Author: joepio

lib/src/store.ts

@@ -420,7 +420,7 @@ export class Store {
     if (agent) {
       setCookieAuthentication(this, agent);
       this.webSockets.forEach(ws => {
-        authenticate(ws, this);
+        ws.readyState === ws.OPEN && authenticate(ws, this);
       });
       this.resources.forEach(r => {
         if (r.isUnauthorized()) {
@@ -434,7 +434,7 @@ export class Store {
   public setServerUrl(url: string): void {
     tryValidURL(url);
 
-    if (url.substr(-1) === '/') {
+    if (url.substring(-1) === '/') {
       throw Error('baseUrl should not have a trailing slash');
     }