title: I get "Assertion failed: You must include an `id` in a hash passed to `push` " when querying API
body: <p>I must have read every question on stack overflow regarding my issue and have not found a solution.
  I am very new to Ember and Node so please bear with me.</p>
  
  <p>The server responds with this format:  </p>
  
  <pre><code>{
  "_id" : "53fddf59d72f9b4d3a3e164a"
  "about" : [
      {"from" : "foo"},
      {"text" : "bar"},
      ... ]
  }
  </code></pre>
  
  <p>My model looks like this:</p>
  
  <pre><code>App.About = DS.Model.extend({
      from : DS.attr('string'),
      text : DS.attr('string'),
      ...
  }
  </code></pre>
  
  <p>Adapter &amp; serializer:</p>
  
  <pre><code>App.ApplicationAdapter = DS.RESTAdapter.extend({
      host: 'http://localhost:3000'
  });
  
  App.ApplicationSerializer = DS.JSONSerializer.extend({
      primaryKey: '_id'
  });
  </code></pre>
  
  <p>And my route:</p>
  
  <pre><code>App.AboutRoute = Ember.Route.extend({
      model: function() {
          return this.store.find('about');
      }
  });
  </code></pre>
  
  <p>Using handlebars:</p>
  
  <pre><code>&lt;script type="text/x-handlebars" data-template-name="about"&gt;
      &lt;p&gt;{{from}}&lt;/p&gt;
  &lt;/script&gt;
  </code></pre>
  
  <p>The route will render, but the console gives the error:</p>
  
  <blockquote>
    <p>DEBUG: ------------------------------- ember.js:3285<br>
    DEBUG: Ember      : 1.3.0 ember.js:3285<br>
    DEBUG: Ember Data : 1.0.0-beta.5 ember.js:3285<br>
    DEBUG: Handlebars : 1.3.0 ember.js:3285<br>
    DEBUG: jQuery     : 1.10.2 ember.js:3285<br>
    DEBUG: ------------------------------- ember.js:3285<br>
    generated -> route:application Object {fullName: "route:application"} ember.js:3285<br>
    <strong>Assertion failed: You must include an <code>id</code> in a hash passed to <code>push</code> ember.js:3285</strong><br>
    generated -> controller:about Object {fullName: "controller:about"} ember.js:3285<br>
    Transitioned into 'about'</p>
  </blockquote>
  
  <p>What am I doing wrong?!</p>
  
  <hr>
  
  <p>Update:</p>
  
  <p>Have accepted Kingpin2k's answer even though this was not the exact format I ended up using. See the comments for details.</p>