title: YAML.load_file issue
body: <p>I have a bestiary.yml and test.rb in one directory, and when I try loading my .yml file like that </p>
  
  <pre><code>got_data_1 = YAML.load_file('bestiary.yml')
  </code></pre>
  
  <p>it gives me a </p>
  
  <pre><code>/usr/lib/ruby/2.3.0/psych.rb:471:in `initialize': No such file or directory @ rb_sysopen
  </code></pre>
  
  <p>error. But when I try launching this</p>
  
  <pre><code>got_data = YAML.load(File.open(File.join(File.dirname(__FILE__), 'bestiary.yml')))
  </code></pre>
  
  <p>everything works fine. Why load_file method doesn't work and what's the difference between this two methods? 
  Thank you</p>