title: InvalidRequest when copying file in onedrive
body: <p>When copying a file in onedrive, I get the following error:</p>
  
  <pre><code>onedrivesdk.error.OneDriveError: invalidRequest - ObjectHandle is Invalid
  </code></pre>
  
  <p>This error occurs only when copying to the root file, otherwise it works just fine.</p>
  
  <p>This is how the code looks like:</p>
  
  <pre><code>ref = onedrivesdk.ItemReference()
  ref.id = 'root'
  client.item(drive='me', id='itemtocopy!id').copy(parent_reference=ref).post()
  </code></pre>