title: Change Fastlane execution folder while inside a lane
body: <p>We have a flow where we execute a custom script which copies the project on the desktop before it is signed and submitted.</p>
  
  <p>Now we want to use Fastlane and we were thinking to do the following:</p>
  
  <ol>
  <li>We start the <code>fastlane build</code> process</li>
  <li>We execute the custom <code>sh</code> script</li>
  <li>We do all the <code>fastlane</code> magic</li>
  </ol>
  
  <p>And I am thinking the following - since my sh script is copying the project on the desktop, how can I continue the <code>fastlane</code> script execution from the copied folder and not the original (source) folder?</p>
  
  <p>Should we start <code>fastlane</code> from our custom script instead?</p>