Fixed: set default empty tokens configuration if nothing is passed.

Fixed: NPM on Windows doesn't like path in single quotes.

lib/ClientManager.js

@@ -11,6 +11,8 @@ class ClientManager {
     constructor(opt) {
         this.opt = opt || {};
 
+        this.opt.tokens = this.opt.tokens || {};
+
         // id -> client instance
         this.clients = new Map();
 

package.json

@@ -27,7 +27,7 @@
     "ws": "5.1.1"
   },
   "scripts": {
-    "test": "mocha --check-leaks --require esm './**/*.test.js'",
+    "test": "mocha --check-leaks --require esm ./**/*.test.js",
     "start": "./bin/server",
     "dev": "node-dev bin/server --port 3000"
   }