title: Issue with Trello webhook
body: <p>I'm currently working with Trello's API and I'm trying to set a webhook, but I'm running into issues that hopefully someone can help me resolve. First of all in the Trello API and docs (<a href="https://trello.com/docs/gettingstarted/webhooks.html" rel="nofollow">https://trello.com/docs/gettingstarted/webhooks.html</a>), creating a webhook requires sending the idModel as part of the json. I guess my first problem is that I'm not sure exactly sure what the idModel, or how I can find this id. I tried to use the id I get if I get tokens, but currently I'm getting a 400 response error when I send a request to the following endpoint:</p>
  
  <p><a href="https://trello.com/1/tokens/daf73f1c77efc8f6062aaa94005ab07215d8d390ff2caffe57659707fee32597/webhooks" rel="nofollow">https://trello.com/1/tokens/daf73f1c77efc8f6062aaa94005ab07215d8d390ff2caffe57659707fee32597/webhooks</a></p>
  
  <p>and my json looks something like (replace callbackURL with my actual callback url):</p>
  
  <pre><code>{
   description: "My first webhook",
   callbackURL: callbackURL,
   idModel: "54fdef9430a36282010f6230",
  }
  </code></pre>