Explicitly specify port in 'npm start' script

README.md

@@ -92,20 +92,20 @@ To use the Material theme, import the correspondent file from the `theme/materia
   `vaadin-button.html`
 
 
-## Running demos and tests in browser
+## Running demos and tests in a browser
 
 1. Fork the `vaadin-button` repository and clone it locally.
 
-1. Make sure you have [npm](https://www.npmjs.com/) installed.
+1. Make sure you have [npm](https://www.npmjs.com/) and [Bower](https://bower.io) installed.
 
 1. When in the `vaadin-button` directory, run `npm install` and then `bower install` to install dependencies.
 
 1. Run `npm start`, browser will automatically open the component API documentation.
 
 1. You can also open demo or in-browser tests by adding **demo** or **test** to the URL, for example:
 
-  - http://127.0.0.1:8080/components/vaadin-button/demo
-  - http://127.0.0.1:8080/components/vaadin-button/test
+  - http://127.0.0.1:3000/components/vaadin-button/demo
+  - http://127.0.0.1:3000/components/vaadin-button/test
 
 
 ## Running tests from the command line

package.json

@@ -25,7 +25,7 @@
   "scripts": {
     "test": "wct",
     "prestart": "polymer analyze vaadin-* > analysis.json",
-    "start": "polymer serve --open",
+    "start": "polymer serve --port 3000 --open",
     "preversion": "gulp version:update"
   },
   "devDependencies": {