<firefly-card-tray>
This component is used to render a collection of cards. Each card must have the "card" CSS class, and there must be a paper-dialog that uses the "detail-dialog" class
Install the Polymer-CLI
First, make sure you have the Polymer CLI installed. Then run polymer serve to serve your element locally.
Viewing Your Element
$ polymer serve
Running Tests
$ polymer test
Your application is already set up to be tested via web-component-tester. Run polymer test to run your application's test suite locally.