title: Reading and updating YAML file by ruby code
body: <p>I have written a yml file like this:</p>
  
  <pre><code>last_update: '2014-01-28 11:00:00'
  </code></pre>
  
  <p>I am reading this file as </p>
  
  <pre><code>config = YAML.load('config/data.yml')
  </code></pre>
  
  <p>Later I am accessing the last_update_time as config['last_update'] but it is not working. Also I want to update last_update_time by my ruby code like it should update like:</p>
  
  <pre><code> last_update: '2014-01-29 23:59:59' 
  </code></pre>
  
  <p>I have no idea how to do that.</p>