I ran exactly the following:
dashing new project
cd project
bundle install && dashing start
It listed the "using" output and began the server. Output here.
Visiting localhost:3030 resulted in a plain grey web page with nothing on it but the text Try this: curl -d '{ "auth_token": "YOUR_AUTH_TOKEN", "text": "Hey, Look what I can do!" }' \http://localhost:3030/widgets/welcome at the top of the page. The page's generated source code is here.
Running the curl command, modified to work on Windows, seemed as if it worked, but it changed nothing on the grey webpage.
curl -X POST -H "Content-Type: application/json" -d "{ \"auth_token\": \"YOUR_AUTH_TOKEN\", \"text\": \"Hey, Look what I can do!\" }" http://localhost:3030/widgets/welcome
The console running the server showed the following:
127.0.0.1 - - [02/Jun/2015 11:55:58] "POST /widgets/welcome HTTP/1.1" 204 - 0.0000
I figured it out. You must have Node.JS or some kind of Javascript engine installed.