title: ENOENT no such file on Express Endpoint for readFileSync
body: <p>I've been going slightly crazy trying to figure this out. I have some certs that I need to pass through to an authentication client from my api; however, the application continues to throw ENOENT exceptions even though the file clearly exists within the same directory (I've fiddled with this to make sure). I'm using readFileSync, effectively doing the following:</p>
  
  <pre><code>key:    fs.readFileSync('./privateKey.pem'),
  </code></pre>
  
  <p>Strangely, if I run this on a standalone Node server not as a part of an api, the file is able to be found without a problem.  Is there some consideration I'm not aware of when trying to use readFileSync in such a scenario?</p>
  
  <p>Thanks!</p>