title: Group date by date and count rows
body: <p>I have a log table.
  I want to generate a fancy graph where we can see the total logs counts per day.</p>
  
  <p>The output I want =</p>
  
  <pre><code>2014-01-05 =&gt; 1
  2014-01-06 =&gt; 6
  </code></pre>
  
  <p>Where the first is the date then the totals logs within that date.</p>
  
  <p>I currently have this</p>
  
  <pre><code>Log.order('created_at desc').limit(60).group('created_at')
  </code></pre>
  
  <p>Can't figure it out, if you guys would help me :)</p>
  
  <p>Log example:</p>
  
  <pre><code>#&lt;Log id: 33533, user_id: 94, category: 19, sub_category: 15147, data: {}, created_at: "2014-12-14 11:40:32", updated_at: "2014-12-14 11:40:32"&gt;
  </code></pre>